CVE-2026-91937: Flowise before 3.1.4 NoSQL Injection via sessionId
Flowise before 3.1.4 fails to sanitize the overrideConfig.sessionId parameter before using it in MongoDB queries within the MongoDBMemory node. Unauthenticated attackers can submit MongoDB operator objects through the prediction API to read chat history records belonging to other users from the shared collection.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Flowiseto a version that resolves this vulnerability.Fixed in 3.1.4 - Compensating control
Restrict access to the prediction API (unauthenticated attackers can submit crafted MongoDB operator objects via prediction API using overrideConfig.sessionId to read other users' chat history from the shared MongoDB collection).
Event History
Frequently Asked Questions
Which deployments are exposed?
Flowise deployments before 3.1.4 that use the MongoDBMemory node and expose the prediction API are affected. The issue concerns chat histories stored in a shared MongoDB collection.
What does an attacker need to exploit this issue?
An attacker does not need authentication or user interaction. They can submit MongoDB operator objects in overrideConfig.sessionId through the prediction API.
What can an attacker access?
Successful exploitation can allow reading chat history records that belong to other users. The provided information describes confidentiality impact only, not modification or deletion of records.
How can I determine whether my deployment is affected?
Check whether the Flowise version is earlier than 3.1.4 and whether flows use the MongoDBMemory node. Also review whether the prediction API accepts overrideConfig.sessionId input.