CRITICAL Langflow: Langflow CVE-2026-55255 — IDOR lets users run (and loot) other users' flows
Why it matters
On multi-user Langflow, any logged-in user can execute anyone else's flows and read the credentials embedded in them. Being actively used for API key theft. Single-user instances are less exposed, but the fix is one upgrade.
Fix it — 3 steps
- Upgrade to Langflow 1.9.1 or later — the IDOR in /api/v1/responses is closed there.
- Review user accounts: anyone who should not be there is a credential-theft risk on a vulnerable version.
- Rotate flow credentials if you ran a vulnerable version with multiple users.
Verify it’s fixed
curl -s http://YOUR_SERVER_IP:7860/api/v1/version # must be >= 1.9.1
References
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