CVE-2026-8505criticalBroken access control2026-10-05
CVE-2026-8505: Langflow webhooks let anyone run a flow without an API key
In Langflow 1.7.0 through 1.9.0, webhook endpoints skipped API key checks by default, so anyone who knew a flow's UUID could run it as the flow's owner. Flows that run Python code turn that into remote code execution.
What it is
Langflow's maintainers: when WEBHOOK_AUTH_ENABLE is False, AuthService.get_webhook_user returns the flow owner without checking the API key in the request.
That setting was added in 1.7.0 with a default of False, so every webhook endpoint was public in 1.7.0 through 1.9.0, protected only by the secrecy of the flow ID.
The advisory lists remote code execution (through flows with code-running components), denial of service by triggering heavy flows, and unwanted changes to databases or systems a flow connects to.
How to check
- Affected: langflow (pip) >= 1.7.0, <= 1.9.0.
- If you set LANGFLOW_WEBHOOK_AUTH_ENABLE=false on purpose, your webhooks stay public even after upgrading.
How to fix
- Upgrade langflow to 1.9.1 or later. That release changes the default of WEBHOOK_AUTH_ENABLE to True, so webhooks need an API key and owner check.
- Don't set LANGFLOW_WEBHOOK_AUTH_ENABLE=false on an instance reachable from the internet.
pip show langflow | grep VersionSources
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