CVE-2026-8446 is an authentication bypass vulnerability affecting IBM Langflow OSS versions 1.0.0 through 1.10.3. The flaw exists in the Model Context Protocol (MCP) composer endpoint when mcp_composer_enabled=true and projects are configured with auth_type=oauth. This configuration allows bypassing authentication controls, classified under CWE-306 (Missing Authentication for Critical Function). The vulnerability has a CVSS 3.1 base score of 7.5, indicating high severity, with network attack vector, no privileges required, and no user interaction needed. No vendor advisory or patch information is currently available.

An attacker can bypass authentication on the MCP composer endpoint under the specified configuration, potentially gaining unauthorized access to critical functions or sensitive data. The vulnerability does not impact integrity or availability but has a high confidentiality impact. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider disabling the MCP composer feature (mcp_composer_enabled) if feasible or restricting access to the endpoint through network controls. Monitor IBM advisories for updates on patches or official mitigations.