CVE-2026-55255
Description
CVE-2026-55255 is a high-severity IDOR vulnerability in Langflow versions before 1.9.1, allowing authenticated attackers to execute unauthorized AI flows.
CPE
| Product | Version Start | Version End (excl.) | Status |
|---|---|---|---|
| langflow | * | 1.9.1 | vulnerable |
Related weakness (CWE)
Remediation plan
Apply official patches
Immediately upgrade Langflow installations to version 1.9.1 or later. This version introduces proper authorization checks on the /api/v1/responses endpoint to prevent IDOR attacks.
Update affected systems
Identify all instances of Langflow in your environment running versions earlier than 1.9.1. Ensure that all container images, local installations, and cloud-hosted environments are updated to the patched version.
Restrict access
Implement strict network access controls and ensure that the Langflow API is not exposed to the public internet. Use robust identity and access management (IAM) to limit authenticated access to trusted users only.
Monitor for exploitation
Review application logs for suspicious activity on the /api/v1/responses endpoint. Look for patterns where a single authenticated user attempts to access or execute multiple flow IDs that do not belong to their account.
Detection Guidance
"Detect exploitation by monitoring web server and application logs for HTTP requests to the /api/v1/responses endpoint. Specifically, look for authenticated sessions that reference flow IDs inconsistent with the user's historical activity or assigned permissions. Security teams should implement signatures to identify rapid-fire requests to this endpoint, which may indicate an attacker enumerating flow IDs to execute unauthorized AI workflows."