diff --git a/src/controller/conversation.controller/conversation.controller.js b/src/controller/conversation.controller/conversation.controller.js
index 73d5335bf..1b4dbb3ad 100644
--- a/src/controller/conversation.controller/conversation.controller.js
+++ b/src/controller/conversation.controller/conversation.controller.js
@@ -2,6 +2,8 @@ const mongoose = require('mongoose')
 const logger = require('../../middleware/logger')
 const getConstants = require('../../../src/constants').getConstants
 const CONSTANTS = getConstants()
+const errors = require('./error')
+const error = new errors.ConversationControllerError()
 
 async function getAllConversations (req, res, next) {
   const repo = req.ctx.repositories.getConversationRepository()
@@ -42,8 +44,8 @@ async function createConversationForTargetUUID (req, res, next) {
 
     const user = await userRepo.findOneByUsernameAndOrgShortname(requesterUsername, requesterOrg, { session })
 
-    if (!body.body) {
-      return res.status(400).json({ message: 'Missing required field body' })
+    if (typeof body !== 'object' || !body.body || !repo.validateConversation(body)) {
+      return res.status(400).json(error.invalidConversationObject())
     }
 
     const result = await repo.createConversation(targetUUID, body, user, true, { session })
@@ -73,8 +75,56 @@ async function createConversationForTargetUUID (req, res, next) {
   }
 }
 
+async function updateConversationByUUID (req, res, next) {
+  const session = await mongoose.startSession()
+
+  try {
+    session.startTransaction()
+
+    const repo = req.ctx.repositories.getConversationRepository()
+    const conversationUUID = req.params.uuid
+    const body = req.body
+
+    // Check if conversation exists
+    const conversation = await repo.findOneByUUID(conversationUUID, { session })
+    if (!conversation) {
+      logger.info({ uuid: req.ctx.uuid, message: `No conversation found with UUID ${conversationUUID}` })
+      return res.status(404).json(error.conversationDne(conversationUUID))
+    }
+
+    // Validate body
+    if (typeof body !== 'object' || !(body.body || body.visibility) || !repo.validateConversation(body)) {
+      logger.info({ uuid: req.ctx.uuid, message: 'The conversation could not be edited because the request body was invalid.' })
+      return res.status(400).json(error.invalidConversationEditObject())
+    }
+
+    const result = await repo.editConversation(conversationUUID, body, { session })
+    await session.commitTransaction()
+    return res.status(200).json(result)
+  } catch (err) {
+    if (session && session.inTransaction()) {
+      await session.abortTransaction()
+    }
+    next(err)
+  } finally {
+    if (session && session.id) {
+      // Check if session is still valid before trying to end
+      try {
+        await session.endSession()
+      } catch (sessionEndError) {
+        logger.error({
+          uuid: req.ctx.uuid,
+          message: 'Error ending session in finally block',
+          error: sessionEndError
+        })
+      }
+    }
+  }
+}
+
 module.exports = {
   getAllConversations,
   getConversationsForTargetUUID,
-  createConversationForTargetUUID
+  createConversationForTargetUUID,
+  updateConversationByUUID
 }
diff --git a/src/controller/conversation.controller/error.js b/src/controller/conversation.controller/error.js
new file mode 100644
index 000000000..8d116c691
--- /dev/null
+++ b/src/controller/conversation.controller/error.js
@@ -0,0 +1,49 @@
+const idrErr = require('../../utils/error')
+
+class ConversationControllerError extends idrErr.IDRError {
+  conversationDne (uuid) {
+    const err = {}
+    err.error = 'CONVERSATION_DNE'
+    err.message = `The conversation with UUID ${uuid} does not exist.`
+    return err
+  }
+
+  conversationIndexDne (shortname, index) {
+    const err = {}
+    err.error = 'CONVERSATION_INDEX_DNE'
+    err.message = `No conversation exists at index ${index} for the ${shortname} organization.`
+    return err
+  }
+
+  notAllowedToEditConversation () {
+    const err = {}
+    err.error = 'NOT_ALLOWED_TO_EDIT_CONVERSATION'
+    err.message = 'You must be the original author or Secretariat to edit this conversation.'
+    return err
+  }
+
+  notAllowedToChangeConversationVisibility () {
+    const err = {}
+    err.error = 'NOT_ALLOWED_TO_CHANGE_CONVERSATION_VISIBILITY'
+    err.message = 'Only the Secretariat is allowed to change the visibility of a conversation.'
+    return err
+  }
+
+  invalidConversationObject () {
+    const err = {}
+    err.error = 'BAD_INPUT'
+    err.message = "Parameters were invalid: conversation object must include property 'body' (string) and optionally 'visibility' ('public' or 'private')."
+    return err
+  }
+
+  invalidConversationEditObject () {
+    const err = {}
+    err.error = 'BAD_INPUT'
+    err.message = "Parameters were invalid: conversation object must include at least one of the following properties: 'body' (string) or 'visibility' ('public' or 'private')."
+    return err
+  }
+}
+
+module.exports = {
+  ConversationControllerError
+}
diff --git a/src/controller/conversation.controller/index.js b/src/controller/conversation.controller/index.js
index 421cc8e5e..45eeeee53 100644
--- a/src/controller/conversation.controller/index.js
+++ b/src/controller/conversation.controller/index.js
@@ -257,4 +257,99 @@ router.post('/conversation/target/:uuid',
   controller.createConversationForTargetUUID
 )
 
+// Update conversation - SEC only
+router.put('/conversation/:uuid',
+  /*
+  #swagger.tags = ['Conversation']
+  #swagger.operationId = 'updateConversationByUUID'
+  #swagger.summary = "Updates a conversation by UUID (accessible to Secretariat only)"
+  #swagger.description = "
+        <h2>Access Control</h2>
+        <p>User must belong to an organization with the <b>Secretariat</b> role</p>
+        <h2>Expected Behavior</h2>
+        <p><b>Secretariat:</b> Updates the conversation with the specified UUID</p>"
+  #swagger.parameters['uuid'] = { description: 'The UUID of the conversation to update' }
+  #swagger.parameters['$ref'] = [
+    '#/components/parameters/apiEntityHeader',
+    '#/components/parameters/apiUserHeader',
+    '#/components/parameters/apiSecretHeader'
+  ]
+  #swagger.requestBody = {
+    required: true,
+    content: {
+      'application/json': {
+        schema: {
+          type: 'object',
+          properties: {
+            body: {
+              type: 'string',
+              description: 'The updated content of the conversation message'
+            },
+            visibility: {
+              type: 'string',
+              enum: ['private', 'public'],
+              description: 'The updated visibility of the conversation message'
+            }
+          }
+        }
+      }
+    }
+  }
+  #swagger.responses[200] = {
+    description: 'Returns the updated conversation',
+    content: {
+      "application/json": {
+        schema: {
+          $ref: '../schemas/conversation/conversation.json'
+        }
+      }
+    }
+  }
+  #swagger.responses[400] = {
+    description: 'Bad Request',
+    content: {
+      "application/json": {
+        schema: { $ref: '../schemas/errors/bad-request.json' }
+      }
+    }
+  }
+  #swagger.responses[401] = {
+    description: 'Not Authenticated',
+    content: {
+      "application/json": {
+        schema: { $ref: '../schemas/errors/generic.json' }
+      }
+    }
+  }
+  #swagger.responses[403] = {
+    description: 'Forbidden',
+    content: {
+      "application/json": {
+        schema: { $ref: '../schemas/errors/generic.json' }
+      }
+    }
+  }
+  #swagger.responses[404] = {
+    description: 'Not Found',
+    content: {
+      "application/json": {
+        schema: { $ref: '../schemas/errors/generic.json' }
+      }
+    }
+  }
+  #swagger.responses[500] = {
+    description: 'Internal Server Error',
+    content: {
+      "application/json": {
+        schema: { $ref: '../schemas/errors/generic.json' }
+      }
+    }
+  }
+  */
+  mw.validateUser,
+  mw.onlySecretariat,
+  param(['uuid']).isUUID(4),
+  controller.updateConversationByUUID
+)
+
 module.exports = router
diff --git a/src/controller/registry-org.controller/error.js b/src/controller/registry-org.controller/error.js
index d4af5f1e6..dd5ffe352 100644
--- a/src/controller/registry-org.controller/error.js
+++ b/src/controller/registry-org.controller/error.js
@@ -91,34 +91,6 @@ class RegistryOrgControllerError extends idrErr.IDRError {
     err.message = 'The requested user can not be created and added to the organization because the organization has hit its limit of 100 users. Contact the Secretariat.'
     return err
   }
-
-  conversationDne (shortname, index) {
-    const err = {}
-    err.error = 'CONVERSATION_DNE'
-    err.message = `The conversation at index ${index} does not exist for the ${shortname} organization.`
-    return err
-  }
-
-  notAllowedToEditConversation () {
-    const err = {}
-    err.error = 'NOT_ALLOWED_TO_EDIT_CONVERSATION'
-    err.message = 'You must be the original author or Secretariat to edit this conversation.'
-    return err
-  }
-
-  notAllowedToChangeConversationVisibility () {
-    const err = {}
-    err.error = 'NOT_ALLOWED_TO_CHANGE_CONVERSATION_VISIBILITY'
-    err.message = 'Only the Secretariat is allowed to change the visibility of a conversation.'
-    return err
-  }
-
-  invalidConversationObject () {
-    const err = {}
-    err.error = 'BAD_INPUT'
-    err.message = 'Parameters were invalid: conversation must be an object with a body.'
-    return err
-  }
 }
 
 module.exports = {
diff --git a/src/controller/registry-org.controller/registry-org.controller.js b/src/controller/registry-org.controller/registry-org.controller.js
index 64da4d038..8d4292079 100644
--- a/src/controller/registry-org.controller/registry-org.controller.js
+++ b/src/controller/registry-org.controller/registry-org.controller.js
@@ -4,6 +4,8 @@ const { getConstants } = require('../../constants')
 const _ = require('lodash')
 const errors = require('./error')
 const error = new errors.RegistryOrgControllerError()
+const conversationErrors = require('../conversation.controller/error')
+const convoError = new conversationErrors.ConversationControllerError()
 const validateUUID = require('uuid').validate
 
 /**
@@ -241,10 +243,6 @@ async function updateOrg (req, res, next) {
     let updatedOrg
     let jointApprovalRequired
 
-    if (conversation && (typeof conversation !== 'object' || !conversation.body)) {
-      return res.status(400).json(error.invalidConversationObject())
-    }
-
     try {
       session.startTransaction()
       const isSecretariat = await repo.isSecretariatByShortName(req.ctx.org, { session })
@@ -280,6 +278,7 @@ async function updateOrg (req, res, next) {
         }
       }
 
+      // Validate org
       const result = repo.validateOrg(body, { session })
       if (!result.isValid) {
         logger.error(JSON.stringify({ uuid: req.ctx.uuid, message: 'CVE JSON schema validation FAILED.' }))
@@ -287,6 +286,19 @@ async function updateOrg (req, res, next) {
         return res.status(400).json({ message: 'Parameters were invalid', errors: result.errors })
       }
 
+      // Validate conversation (if it exists)
+      if (conversation) {
+        if (
+          typeof conversation !== 'object' ||
+          !conversation.body ||
+          !conversationRepo.validateConversation(conversation)
+        ) {
+          logger.error(JSON.stringify({ uuid: req.ctx.uuid, message: 'Invalid conversation object.' }))
+          await session.abortTransaction()
+          return res.status(400).json(convoError.invalidConversationObject())
+        }
+      }
+
       // Check for duplicate short_name
       if (body?.short_name !== shortName && await repo.orgExists(body?.short_name, { session })) {
         logger.info({
@@ -634,7 +646,17 @@ async function editConversationForOrg (req, res, next) {
       const conversation = await conversationRepo.findByTargetUUIDAndIndex(orgUUID, index, { session })
       if (!conversation) {
         logger.info({ uuid: req.ctx.uuid, message: `The conversation at index ${index} does not exist for the ${orgShortName} organization.` })
-        return res.status(404).json(error.conversationDne(orgShortName, index))
+        return res.status(404).json(convoError.conversationIndexDne(orgShortName, index))
+      }
+
+      // Validate body
+      if (
+        typeof incomingParameters !== 'object' ||
+        !(incomingParameters.body || incomingParameters.visibility) ||
+        !conversationRepo.validateConversation(incomingParameters)
+      ) {
+        logger.info({ uuid: req.ctx.uuid, message: 'The conversation could not be edited because the request body was invalid.' })
+        return res.status(400).json(convoError.invalidConversationObject())
       }
 
       // Check if user has permissions to edit conversation
@@ -642,13 +664,13 @@ async function editConversationForOrg (req, res, next) {
       const userUUID = await userRepo.getUserUUID(requesterUsername, req.ctx.org, { session })
       if (conversation.author_id !== userUUID && !isSecretariat) {
         logger.info({ uuid: req.ctx.uuid, message: 'The user does not have permission to edit this conversation.' })
-        return res.status(403).json(error.notAllowedToEditConversation())
+        return res.status(403).json(convoError.notAllowedToEditConversation())
       }
 
       // Check if user has permission to change visibility of conversation
       if (incomingParameters.visibility && !isSecretariat) {
         logger.info({ uuid: req.ctx.uuid, message: 'Only the Secretariat is allowed to change the visibility of a conversation.' })
-        return res.status(403).json(error.notAllowedToChangeConversationVisibility())
+        return res.status(403).json(convoError.notAllowedToChangeConversationVisibility())
       }
 
       // Make the edit
diff --git a/src/repositories/conversationRepository.js b/src/repositories/conversationRepository.js
index 02a61d807..c8a8d48cc 100644
--- a/src/repositories/conversationRepository.js
+++ b/src/repositories/conversationRepository.js
@@ -62,6 +62,13 @@ class ConversationRepository extends BaseRepository {
     return conversation[0]
   }
 
+  validateConversation (conversation) {
+    if ((conversation.body && typeof conversation.body !== 'string') || (conversation.visibility && !['public', 'private'].includes(conversation.visibility))) {
+      return false
+    }
+    return true
+  }
+
   async createConversation (targetUUID, body, user, isSecretariat, options = {}) {
     const { getUserFullName } = require('../utils/utils')
     const newUUID = uuid.v4()
diff --git a/test/integration-tests/conversation/conversationTest.js b/test/integration-tests/conversation/conversationTest.js
index 802199ff2..d2c5db976 100644
--- a/test/integration-tests/conversation/conversationTest.js
+++ b/test/integration-tests/conversation/conversationTest.js
@@ -145,6 +145,28 @@ describe('Testing Conversation endpoints', () => {
           })
         })
     })
+    it('Should update a conversation by UUID as Secretariat', async () => {
+      await chai.request(app)
+        .put(`/api/conversation/${rootConvoUUID}`)
+        .set(constants.headers)
+        .send({
+          body: 'test updated',
+          visibility: 'private'
+        })
+        .then((res, err) => {
+          expect(err).to.be.undefined
+          expect(res).to.have.status(200)
+
+          expect(res.body).to.haveOwnProperty('UUID')
+          expect(res.body.UUID).to.equal(rootConvoUUID)
+
+          expect(res.body).to.haveOwnProperty('body')
+          expect(res.body.body).to.equal('test updated')
+
+          expect(res.body).to.haveOwnProperty('visibility')
+          expect(res.body.visibility).to.equal('private')
+        })
+    })
   })
 
   context('Negative Tests', () => {
@@ -158,7 +180,53 @@ describe('Testing Conversation endpoints', () => {
           expect(res).to.have.status(400)
 
           expect(res.body).to.haveOwnProperty('message')
-          expect(res.body.message).to.equal('Missing required field body')
+          expect(res.body.message).to.equal("Parameters were invalid: conversation object must include property 'body' (string) and optionally 'visibility' ('public' or 'private').")
+        })
+    })
+    it('Should fail to post a conversation with invalid body', async () => {
+      await chai.request(app)
+        .post(`/api/conversation/target/${orgUUID}`)
+        .set(constants.headers)
+        .send({
+          body: 123
+        })
+        .then((res, err) => {
+          expect(err).to.be.undefined
+          expect(res).to.have.status(400)
+
+          expect(res.body).to.haveOwnProperty('message')
+          expect(res.body.message).to.equal("Parameters were invalid: conversation object must include property 'body' (string) and optionally 'visibility' ('public' or 'private').")
+        })
+    })
+    it('Should fail to update a conversation that does not exist', async () => {
+      await chai.request(app)
+        .put('/api/conversation/non-existent-uuid')
+        .set(constants.headers)
+        .send({
+          body: 'test updated',
+          visibility: 'private'
+        })
+        .then((res, err) => {
+          expect(err).to.be.undefined
+          expect(res).to.have.status(404)
+
+          expect(res.body).to.haveOwnProperty('message')
+          expect(res.body.message).to.equal('The conversation with UUID non-existent-uuid does not exist.')
+        })
+    })
+    it('Should fail to update a conversation with invalid body', async () => {
+      await chai.request(app)
+        .put(`/api/conversation/${rootConvoUUID}`)
+        .set(constants.headers)
+        .send({
+          body: 123
+        })
+        .then((res, err) => {
+          expect(err).to.be.undefined
+          expect(res).to.have.status(400)
+
+          expect(res.body).to.haveOwnProperty('message')
+          expect(res.body.message).to.equal("Parameters were invalid: conversation object must include at least one of the following properties: 'body' (string) or 'visibility' ('public' or 'private').")
         })
     })
   })
diff --git a/test/integration-tests/conversation/editConversationTest.js b/test/integration-tests/conversation/editConversationTest.js
index 08e101f6e..7a219c385 100644
--- a/test/integration-tests/conversation/editConversationTest.js
+++ b/test/integration-tests/conversation/editConversationTest.js
@@ -14,9 +14,8 @@ const orgAdminHeaders = {
   'CVE-API-USER': 'activity_6_admin@activity_6.com'
 }
 
-describe('Testing Conversation endpoints', () => {
+describe('Testing Conversation edit by index endpoint', () => {
   let org
-  // let rootConvoUUID
 
   before(async () => {
     await chai
@@ -181,7 +180,7 @@ describe('Testing Conversation endpoints', () => {
           expect(res).to.have.status(404)
 
           expect(res.body).to.haveOwnProperty('message')
-          expect(res.body.message).to.equal('The conversation at index 5 does not exist for the activity_6 organization.')
+          expect(res.body.message).to.equal('No conversation exists at index 5 for the activity_6 organization.')
         })
     })
     it('Should fail if admin tries to update a conversation they do not own', async () => {