Langflow Authorization Bypass Through User-Controlled Key Vulnerability
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.
MANARTECH SECURITY ALERT
Langflow Authorization Bypass Through User-Controlled Key Vulnerability
CVE Numbers
CVE-2026-55255
Affected Product
Langflow — Langflow
Threat Description
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.
Severity Scale
CRITICALHIGHMEDIUMLOW
Severity
HIGH
Affected Versions
To be reviewed
Recommended Mitigation
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.
Reference Links
https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e
https://github.com/langflow-ai/langflow/pull/12832
https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploited
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255
https://nvd.nist.gov/vuln/detail/CVE-2026-55255
