Langflow · Langflow
CVE-2026-55255
Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
What it is
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.
CISA: 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.
What to do
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.
Deadline for US federal agencies: July 10, 2026
More exploited flaws from Langflow
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Jul 21, 2026 | Inclusion of Functionality from Untrusted Control Sphere | Langflow | Critical 9.8 | 63% |
| May 21, 2026 | Origin Validation Error | Langflow | Critical 9.4 | 93% |
| Mar 25, 2026 | Code Injection | Langflow | Critical 9.3 | 96% |
| May 5, 2025 | Missing Authentication | Langflow | Critical 9.8 | >99.9% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.