BlackTreeIndependent security intelligenceIBM · Langflow OSS
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verifiedIBM Langflow OSS 1.0.0 through 1.10.3 contain an authorization bypass vulnerability in the MemoryComponent that allows authenticated users to access chat history of other users via session_id collision. The MemoryComponent.retrieve_messages and store_message methods filter on session_id without validating flow_id or user_id ownership, enabling cross-user information disclosure through multiple authenticated API endpoints including /api/v1/run/*, /api/v1/responses, and /api/v2/workflow/*. This vulnerability only affects multi-user deployments with LANGFLOW_AUTO_LOGIN=False.
IBM Langflow OSS 1.0.0 through 1.10.3 contain an authorization bypass vulnerability in the MemoryComponent that allows authenticated users to access chat history of other users via session_id collision. The MemoryComponent.retrieve_messages and store_message methods filter on session_id without validating flow_id or user_id ownership, enabling cross-user information disclosure through multiple authenticated API endpoints including /api/v1/run/*, /api/v1/responses, and /api/v2/workflow/*. This vulnerability only affects multi-user deployments with LANGFLOW_AUTO_LOGIN=False.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.
IBM Langflow OSS 1.0.0 through 1.10.3 contain an authorization bypass vulnerability in the MemoryComponent that allows authenticated users to access chat history of other users via session_id collision. The MemoryComponent.retrieve_messages and store_message methods filter on session_id without validating flow_id or user_id ownership, enabling cross-user information disclosure through multiple authenticated API endpoints including /api/v1/run/*, /api/v1/responses, and /api/v2/workflow/*. This vulnerability only affects multi-user deployments with LANGFLOW_AUTO_LOGIN=False.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-639: Authorization Bypass Through User-Controlled Key. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 5 Aug 2026 · Last source change 7 Aug 2026, 12:53 UTC · CWE-639 · Authorization Bypass Through User-Controlled Key
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.