CVE-2026-55255: Langflow | defend.network

What is CVE-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 victim's flow ID in the request. This vulnerability is fixed in 1.9.1.

CVSS8.4 NVD 3.1

SeverityHIGH

Exploitation In the wild In CISA KEV

EPSS1% · P58

Triage statusActive Exploit

ActionPatch immediately

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L

CWECWE-639

NVD published2026-06-23

NVD last modified2026-10-07

Timeline

2026-06-23Published to the U.S. National Vulnerability Database (NVD)
2026-07-07Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
2026-07-10CISA federal remediation deadline (BOD 22-01)
2026-10-07NVD record last updated

CISA Known Exploited Vulnerability

Langflow Authorization Bypass Through User-Controlled Key Vulnerability

Added to KEV2026-07-07

Federal patch deadline2026-07-10

Known ransomware useUnknown

Affected product

Langflow

Remediation Steps

Apply the vendor security update for Langflow Langflow as a priority.
Restrict network exposure of the affected service to trusted sources until patched.
Review logs and detections for indicators of exploitation.
Confirm fixed versions against the official vendor advisory before deploying.

References

Referenced in our briefings & reports

Vulnerability Priority Report – Week 1 of August 2026 (August 3 – 9)
Vulnerability Priority Report – Week 4 of July 2026 (July 27 – August 2)
Vulnerability Priority Report – Week 3 of July 2026 (July 20 – 26)
Vulnerability Priority Report – Week 2 of July 2026 (July 13 – 19)

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🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.