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Vulnerabilities

Vulnerability · CVE-2026-55255

Langflow Authorization Bypass Through User-Controlled Key Vulnerability

Published Jun 23, 2026 · catalog updated Oct 7, 2026 · Langflow Langflow

Patch now

CVE-2026-55255 is in the CISA known-exploited catalog, due Jul 10, 2026. Confirm Langflow Langflow against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
High8.4
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
0.89%
Remediation
Remediation guidance
Affected products
cpe langflow/langflow · vendor Langflow Langflow

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe langflow/langflowversion unspecified
  • vendor Langflow Langflowversion unspecified

How to fix CVE-2026-55255

  • Recommended remediation

    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 due date Jul 10, 2026.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2026-55255 is in the CISA known-exploited catalog, due Jul 10, 2026. Confirm Langflow Langflow against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. 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.

What should an analyst verify?

CWE-639: Authorization Bypass Through User-Controlled Key. EPSS 0.89%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 23, 2026 · Catalog

    Detected

    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.

  2. Jul 7, 2026 · CISA KEV

    Known exploited

    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

  3. Jul 10, 2026 · CISA KEV

    Remediation due

    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

  4. Oct 7, 2026 · Catalog

    Updated

    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.

Sources

  • CISA KEVConfirmed exploitationCVE-2026-55255

    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.gov
  • CVE.orgVulnerability recordCVE-2026-55255

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-55255

    30-day exploitation probability 0.9%

    first.org
  • NIST NVDVulnerability recordCVE-2026-55255

    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 v

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-55255

    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.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.