CVE-2026-55255
Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-07-07. Federal due date: 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.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | langflow | < 1.9.1 | 1.9.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Langflow | Langflow | before 1.9.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- CISA KEV catalog
- https://github.com/advisories/GHSA-qrpv-q767-xqq2
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
- https://github.com/langflow-ai/langflow/pull/12832
- https://nvd.nist.gov/vuln/detail/CVE-2026-55255
- https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e
- https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-221.yaml
- 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