CVE-2026-59822
Published:July 08, 2026
Updated:August 04, 2026
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, LiteLLM's MCP Streamable HTTP endpoint allowed an unauthenticated attacker to use a fabricated Authorization header to trigger an OAuth2 passthrough fallback path that replaced failed LiteLLM key validation with an empty UserAPIKeyAuth() object, allowing requests to reach MCP tooling without a valid LiteLLM key. This issue is fixed in version 1.84.0.
Affected Packages
litellm (CONDA):
Affected version(s) >=1.34.0 <1.84.0Fix Suggestion:
Update to version 1.84.0litellm (CONDA):
Affected version(s) >=1.34.0 <1.84.0Fix Suggestion:
Update to version 1.84.0litellm (PYTHON):
Affected version(s) >=0.1.0 <1.84.0Fix Suggestion:
Update to version 1.84.0litellm (PYTHON):
Affected version(s) >=0.1.0 <1.84.0Fix Suggestion:
Update to version 1.84.0Related Resources (9)
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Contact UsCVSS v4
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.25