CVE entry · CVE-2026-55255
CVE-2026-55255: Langflow Authorization Bypass Through User-Controlled Key Vulnerability
Langflow contains an authorization bypass through user-controlled key vulnerability which allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request.
- Actively exploited: added to CISA’s KEV catalog on July 7, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: July 10, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes Langflow, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.