CVE-2026-55255
Langflow: IDOR Vulnerability in /api/v1/responses Endpoint Allows Authenticated Attackers to Access Another User's Flow
- Published
- Jun 23, 2026
- Updated
- Oct 7, 2026
- Assigning CNA
- GitHub_M
- Evidence observed
- Jul 7, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:LLow · next 30 days
- Percentile
- 58.6%
- Model date
- Oct 17, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
CISA Known Exploited
This CVE appears in the CISA Known Exploited Vulnerabilities catalog.
Summary
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.
Sources
Local Docker lab for reproducing CVE-2026-55255, an IDOR vulnerability in Langflow's Responses API. Validates cross-user flow execution in vulnerable vs. patched versions with a request-based PoC.
Responsible use
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