CVE-2026-55255Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow
- 8.4HighCVSS base score
- 0.89%Exploitation in 30 daysEPSS · top 40% of all CVEs
- YesKnown exploitedin CISA's KEV since 7 Jul 2026
- YesPublic exploitsa reference or SSVC says so
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Langflow Authorization Bypass Through User-Controlled Key Vulnerability.
- Added
- 7 Jul 2026
- Fix due (US federal)
- 10 Jul 2026
- Used by ransomware
- Not known
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.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 7 Jul 2026.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: it is being exploited.
Show the exploits1
References tagged exploit1 reference
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 7 days later
· 7 days later
Published
- 14 days later
· 14 days later
Added to CISA KEV
Known exploited in the wild
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L |
| NVDNVD · Analyzed | 3.1 | High8.4 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L |
- EPSS (exploitation in 30 days)
- 0.89% · top 40% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.4.
Affected products
- affected < 1.9.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIlangflowGHSA-qrpv-q767-xqq2 (opens in a new tab)
References
References5
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/langflow-ai/langflow/pull/12832 (opens in a new tab)x_refsource_MISC
- https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e (opens in a new tab)x_refsource_MISC
- https://webflow.sysdig.com/blog/understanding-langflow-cve-2026-55255-and-why-higher-cvss-vulnerabilities-arent-always-the-most-exploited (opens in a new tab)third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55255 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-38517 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-qrpv-q767-xqq2 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55255)Record last updated .