CVE-2026-12773

HIGH 7.3

BerriAI litellm MCP Proxy user_api_key_auth_mcp.py UserAPIKeyAuth improper authentication

CVSS Score

7.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-287
Vendor	berriai
Product	litellm
Published	Jun 21, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:R

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

BerriAI / litellm

1.59.0 1.59.1 1.59.2 1.59.3 1.59.4 1.59.5 1.59.6 1.59.7 1.59.8

References

NVD ↗ CVE.org ↗ EPSS Data ↗

vuldb.com: https://vuldb.com/vuln/372515 vuldb.com: https://vuldb.com/vuln/372515/cti vuldb.com: https://vuldb.com/cve/CVE-2026-12773 vuldb.com: https://vuldb.com/submit/811282 gist.github.com: https://gist.github.com/YLChen-007/3cfaad10a69d7a15e4d4d458cb53309e

Credits

🔍 Eric-c (VulDB User) VulDB CNA Team