Advisoriesby IbisLiteLLMGHSA-4jcj-7x88-m979
LiteLLM: MCP Proxy Has Improper Authentication
Fix: upgrade to 1.84.0 or later
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 versions
| Package | Affected | Fixed in |
|---|---|---|
| litellm PyPI | < 1.84.0 | 1.84.0 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-287, CWE-303
- Also known as
- CVE-2026-12773, PYSEC-2026-4067
- nvd.nist.gov/vuln/detail/CVE-2026-12773
- github.com/BerriAI/litellm/commit/73869f0faf7d11ee21adcb5f91b8c33a340b6c2c
- 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
- 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
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All LiteLLM
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