CVE-2026-55255

Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow

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.

Scores

Weaknesses (CWE)

• CWE-639

Advisories

• GHSA-qrpv-q767-xqq2 — Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
• PYSEC-2026-221 — Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.2, an Insecure Direct Object Reference (IDOR) vulnerability in /api/

European references

• ENISA EUVD · EUVD-2026-38517
• GCVE · GCVE-0-2026-55255

Affected configurations (NVD CPE)

• cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:* < 1.9.1

Affected products

References

• https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
• https://github.com/langflow-ai/langflow/pull/12832
• https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e
• 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

Sources