Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
68Vexday Risk Score
Prioritize patching. It exploitation observed by VulnCheck and has a public proof of concept.
ssvc Actcvss 8.4epss 29%
from disclosure to weapon7 days
Published on NVDJun 23
1st PoC+7d
VulnCheck+3d
exploitation probability
29%top 2% of all CVEs
observed exploitation
yesVulnCheck
2 public exploit(s)
Action required by CISAfederal deadline: 2026-07-10
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.
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/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
Affected products
langflow-ai · langflowpublic PoCs found — 2
githubgithub.com/rootdirective-sec/CVE-2026-55255-Lab★ 0vulncheckvulncheck.com/xdb/84a4b14ed683unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
References
https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060ehttps://github.com/langflow-ai/langflow/pull/12832https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploitedhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255