CVE-2026-55255
Langflow: Authorization Bypass Through User-Controlled Key
As of , CVE-2026-55255 in Langflow is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch now.
- Exploited
- Yes: CISA listed it on 7 July 2026
- US federal deadline
- 10 July 20263 days after CISA listed it. US federal civilian agencies must fix it by then.
- Used in ransomware campaigns
- Not known to CISA
- Forensic triage
- Required by CISA under BOD 26-04Agencies must also look for signs that attackers already got in.
- EPSS score
- 0.01Higher than 57% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
- Public exploit
- None foundNeither Metasploit nor Exploit-DB lists one.
- Fix
- Vendor advice: github.comLinks below, from CISA's entry.
What CISA says to do
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.
CISA's required action
What the flaw is
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.
CISA's 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.
The CVE record's description, from GitHub_M
- CVE published
- 23 June 2026
- Assigned by
- GitHub_M
- CVSS
- 8.4 High (CVSS 3.1, from the CNA)
- CWE-639
- Authorization Bypass Through User-Controlled Key
- CISA SSVC, exploitation
- active
- CISA SSVC, automatable
- no
- CISA SSVC, technical impact
- total
Timeline
- The CVE record was published.
- CISA added it to its list of exploited vulnerabilities.
- The US federal deadline to fix it.
Langflow: other exploited entries
| Vulnerability | Product | Our group | Listed | Deadline | EPSS |
|---|---|---|---|---|---|
| CVE-2026-0770Inclusion of Functionality from Untrusted Control Sphere | Langflow Langflow | Patch nowForensic triage required by CISA; Metasploit module | 0.63 | ||
| CVE-2025-3248Missing Authentication | Langflow Langflow | Patch this weekRansomware use; Metasploit module; EPSS 0.99 | 0.99 | ||
| CVE-2026-33017Code Injection | Langflow Langflow | Patch this weekMetasploit module | 0.25 | ||
| CVE-2025-34291Origin Validation Error | Langflow Langflow | Patch this weekEPSS 0.93 | 0.93 |
Read further
- CVE recordcve.org
- NVD entrynvd.nist.gov
- CISA's catalogcisa.gov
- EPSS for this CVEapi.first.org