CVE-2026-12773
BerriAI litellm MCP Proxy user_api_key_auth_mcp.py UserAPIKeyAuth improper authentication
MEDIUM 5.5EPSS 1.0%
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
- BerriAI · litellm
- CVSS v4.0 VULDB
- 5.5 MEDIUM
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v4.0 GitHub
- 5.5 MEDIUM
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 - CVSS v3.1 NVD
- 9.8 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS v3.1 CNA
- 7.3 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - CVSS v2.0 VULDB
- 7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P - EPSS
- 1.02% chance of exploitation in the next 30 days, 63rd percentile
- Published
- 2026-06-21
- Updated
- 2026-07-15
Proof-of-concept exploits (1)
Security advisories
- https://vuldb.com/cve/CVE-2026-12773
- https://vuldb.com/submit/811282
- https://vuldb.com/vuln/372515
- advisories/GHSA-4jcj-7x88-m979