CVE-2026-55255
Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
- Added
- Jul 7, 2026
- Fix due
- Jul 10, 2026
- Ransomware
- Not known
- Published
- Jun 23, 2026
- Updated
- Oct 7, 2026
- First covered
- Jul 8, 2026
- Latest story
- 4 months ago
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.
CWE-639Authorization Bypass Through User-Controlled Key
Attack profile
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:LCISA required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected products
- langflow< 1.9.1