PYSEC-2026-4067
LiteLLM: MCP Proxy Has Improper Authentication
At a glance
- Published
- Updated
- CVE
- CVE-2026-12773
- Aliases
- GHSA-4jcj-7x88-m979
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
Description
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.
Affected packages
| Package | Versions |
|---|---|
| PyPI · litellm | introduced 0, fixed 1.84.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-12773 ADVISORY
- https://github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c WEB
- https://access.redhat.com/security/cve/CVE-2026-12773 WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2491112 WEB
- https://gist.github.com/YLChen-007/3cfaad10a69d7a15e4d4d458cb53309e WEB
- https://github.com/BerriAI/litellm PACKAGE
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12773.json WEB
- https://vuldb.com/cve/CVE-2026-12773 WEB
- https://vuldb.com/submit/811282 WEB
- https://vuldb.com/vuln/372515 WEB
- https://vuldb.com/vuln/372515/cti WEB
- https://pypi.org/project/litellm PACKAGE
- https://github.com/advisories/GHSA-4jcj-7x88-m979 ADVISORY
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — PyPA Advisory Database |