CVE-2026-55255
Langflow Authorization Bypass Through User-Controlled Key Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 10 July 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 8.4 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
- EPSS
- 0.89% probability · 57th percentile
- CISA KEV
- Listed 7 July 2026 · due 10 July 2026
- Weakness
- CWE-639
- Affected
- langflow/langflow
- Source
- security-advisories@github.com
CISA notes
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. https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-55255
References
- https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060ePatch
- https://github.com/langflow-ai/langflow/pull/12832Issue Tracking, Patch
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2Exploit, Mitigation, Vendor Advisory
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2Exploit, Mitigation, Vendor Advisory
- https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploitedThird Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.