CVE-2026-12773: LiteLLM: MCP Proxy Has Improper Authentication
(updated )
A weakness has been identified in BerriAI litellm up to 1.59.8. Affected is the function UserAPIKeyAuth of the file litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py of the component MCP Proxy. Executing a manipulation can lead to improper authentication. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure.
References
- access.redhat.com/security/cve/CVE-2026-12773
- bugzilla.redhat.com/show_bug.cgi?id=2491112
- gist.github.com/YLChen-007/3cfaad10a69d7a15e4d4d458cb53309e
- github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c
- github.com/advisories/GHSA-4jcj-7x88-m979
- nvd.nist.gov/vuln/detail/CVE-2026-12773
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12773.json
- vuldb.com/cve/CVE-2026-12773
- vuldb.com/submit/811282
- vuldb.com/vuln/372515
- vuldb.com/vuln/372515/cti
Code Behaviors & Features
Detect and mitigate CVE-2026-12773 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →