CVE-2026-34046 PUBLISHED

Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check

Assigner: GitHub_M
Reserved: 25.03.2026 Published: 27.03.2026 Updated: 27.03.2026

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.5.1, the _read_flow helper in src/backend/base/langflow/api/v1/flows.py branched on the AUTO_LOGIN setting to decide whether to filter by user_id. When AUTO_LOGIN was False (i.e., authentication was enabled), neither branch enforced an ownership check — the query returned any flow matching the given UUID regardless of who owned it. This allowed any authenticated user to read any other user's flow, including embedded plaintext API keys; modify the logic of another user's AI agents, and/or delete flows belonging to other users. The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with user_id = NULL) under auto-login mode, but inadvertently left the authenticated path without an ownership filter. The fix in version 1.5.1 removes the AUTO_LOGIN conditional entirely and unconditionally scopes the query to the requesting user.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor langflow-ai
Product langflow
Versions
  • Version < 1.5.1 is affected
Vendor langflow-ai
Product langflow-base
Versions
  • Version < 0.5.1 is affected

References

Problem Types

  • CWE-639: Authorization Bypass Through User-Controlled Key CWE
  • CWE-862: Missing Authorization CWE