diff --git a/.Rbuildignore b/.Rbuildignore
index 232504f..c2e551e 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -22,3 +22,5 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^\.jules$
+^\.jules/.*
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a4..c497d8c 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -1,4 +1,4 @@
-## 2024-07-12 - Fix missing parameter validations
-**Vulnerability:** Unvalidated inputs passed to `if()` statements can cause process crashes (`condition has length > 1`) or unexpected coercion vulnerabilities.
-**Learning:** In R, optional boolean parameters that default to `NULL` should be validated using explicit runtime type validation (e.g., `if (!is.null(flag) && (!is.logical(flag) || length(flag) != 1 || is.na(flag)))`).
-**Prevention:** Always implement explicit runtime type validation for optional boolean parameters.
+## 2024-07-17 - Weak Regex Validation Coercion DoS
+**Vulnerability:** Weak regex `^[0-9]+$` used to validate integer input allows excessively large numbers to be entered. When parsed by `as.integer()`, they are coerced to `NA`, bypassing validation and causing runtime crashes or infinite loops when used in `if` conditions.
+**Learning:** The legacy implementation used greedy validation that didn't consider the maximum bounds of `integer` types in R, relying blindly on base numeric characters rather than specific valid options.
+**Prevention:** Use strictly bounded exact-match regex (like `^[12]$`) for discrete choice options to prevent `NA` coercion and subsequent Denial of Service risks.
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 6254651..0cda2f0 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,8 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        # SECURITY: Strictly bounded exact-match regex to prevent DoS from NA coercion of large numbers
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +172,8 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            # SECURITY: Strictly bounded exact-match regex to prevent DoS from NA coercion of large numbers
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +392,8 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            # SECURITY: Strictly bounded exact-match regex to prevent DoS from NA coercion of large numbers
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }