PT-2026-51197

CVE-2026-12773

Published

2026-06-21

Updated

2026-10-01

Description by

CVSS 3.1

9.8

Critical

MetricsAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions BerriAI litellm versions prior to 1.59.9

Description An improper authentication flaw exists in the MCP Proxy component. Specifically, the UserAPIKeyAuth() function within the file litellm/proxy/ experimental/mcp server/auth/user api key auth mcp.py allows remote unauthenticated attackers to bypass API key checks.

Recommendations Update to a version later than 1.59.8. As a temporary workaround, restrict access to the UserAPIKeyAuth() function in the MCP Proxy component to minimize the risk of exploitation.

Exploitability

Exploit

Fix

Impacts

Researchers

Eric-C

Vendors

Affected products

Weakness enumeration

CWE-303: Incorrect Implementation of Authentication Algorithm

CWE-287: Improper Authentication

Related identifiers