CVE-2026-55255

HighActively exploited (CISA KEV)

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.

SeverityHigh
CVSS8.4
Exploit probability—
ProductLangflow
PublishedJun 23, 2026
First seenJun 23, 2026
Added to KEVJul 7, 2026

How to fix

CISA required action

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
Update
  • langflow langflow1.9.1 or later
  • langflow1.9.1, 1.9.2 or later

Affected products

ProductAffected versionsFixed in
langflow langflowv < 1.9.11.9.1
langflowPyPIv < 1.9.1, v < 1.9.21.9.1, 1.9.2

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