CVE-2026-55255
KEVLangflow Authorization Bypass Through User-Controlled Key Vulnerability
Description
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.
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 vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:LPublishedJun 23, 2026
Last modifiedOct 25, 2026
Added to KEVJul 7, 2026
Remediation dueJul 10, 2026
References
- github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060ePatch
- github.com/langflow-ai/langflow/pull/12832Issue TrackingPatch
- github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2ExploitMitigation
- webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploitedThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255US Government Resource
0 recent articles mention this CVE
72
Risk assessment · High
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 109 days
- CVSS
- 8.4 HIGH
- EPSS (30-day exploit probability)
- 0.89% · top 41% of all CVEs
- Weakness
- CWE-639
- Attack vector
- Network, remotely reachable
Recommended actions
- 1.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.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.