Research · Jun 23, 2026 · ZeroDay Catalog
Langflow Authorization Bypass Vulnerability Resolved in Latest Update
An authorization bypass vulnerability in Langflow has been addressed in version 1.9.1, allowing attackers to exploit user-controlled keys to access unauthorized flows.
What changed
Langflow has released an important update to address a critical authorization bypass vulnerability. This flaw, identified as an Insecure Direct Object Reference (IDOR), existed in the /api/v1/responses endpoint, allowing authenticated attackers to manipulate flow IDs and access flows belonging to other users.
The vulnerability has been fixed in version 1.9.1, ensuring that user flows are protected against unauthorized access.
Who is affected
Organizations using Langflow prior to version 1.9.1 are at risk of this vulnerability, particularly those leveraging AI-powered agents and workflows.
Any authenticated user of Langflow could potentially exploit this flaw to access sensitive workflows belonging to other users.
- Langflow users operating versions before 1.9.1.
- Organizations deploying AI workflows through Langflow.
- Developers utilizing Langflow for building AI agents.
What to do
It is crucial for all users of Langflow to upgrade to version 1.9.1 immediately to mitigate the risk posed by this vulnerability. Regularly updating software and monitoring for security advisories can help maintain a secure environment.
Additionally, organizations should review their access controls and user permissions to ensure that unauthorized access is minimized.
- Upgrade Langflow to version 1.9.1 or later.
- Review and tighten access controls for user flows.
- Monitor for any suspicious activity related to flow access.