CVE-2026-91937 FlowiseAI CVE debrief

Who should care

Defenders responsible for Flowise deployments, particularly those using versions prior to 3.1.4, should assess exposure and prioritize remediation to prevent potential data exposure.

Why it matters

CVE-2026-91937 is a high-severity vulnerability in Flowise that allows unauthenticated attackers to read chat history records belonging to other users. Defenders should prioritize verifying Flowise versions, sanitizing user input, and restricting access to sensitive data to prevent potential data exposure.

• Potential unauthorized access to sensitive chat history records
• Possible data exposure due to improper input sanitization
• Need for input validation and sanitization to prevent NoSQL injection attacks
• Verification of Flowise version and deployment configuration required

Technical summary

Flowise before version 3.1.4 is vulnerable to a NoSQL injection attack due to improper sanitization of the overrideConfig.sessionId parameter. This allows unauthenticated attackers to read chat history records belonging to other users from the shared collection. The vulnerability exists within the MongoDBMemory node, where MongoDB queries are executed without proper input validation. Defenders should prioritize verifying Flowise versions and sanitizing user input to prevent potential data exposure and unauthorized access to sensitive chat history records.

Defensive priority

Defenders should prioritize verifying Flowise versions and sanitizing user input to prevent potential data exposure.

Recommended defensive actions

• Verify Flowise version and upgrade to 3.1.4 or later
• Implement input validation and sanitization for user-supplied session IDs
• Review and restrict access to sensitive data and MongoDB queries
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in Flowise before version 3.1.4, which allows unauthenticated attackers to read chat history records belonging to other users. Evidence is limited to CVE and NVD information. Defenders should verify Flowise versions, review MongoDB query sanitization, and assess exposure to potential data breaches.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.