CVE-2026-55255

Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request. This vulnerability is fixed in 1.9.1.

Affected

langflow-ai · langflow

CVSS v3.1 GITHUB

8.4 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L

EPSS

0.89% chance of exploitation in the next 30 days, 59th percentile

CISA KEV

added 2026-07-07

Published

2026-06-23

Updated

2026-10-07

Proof-of-concept exploits (1)

• advisories/GHSA-qrpv-q767-xqq2

Security advisories

• langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
• https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss…
• langflow-ai/langflow/pull/12832

References

• CVE Record
• NVD entry