Improper access control in LiteLLM - CVE-2026-59822
Published: July 1, 2026
Vulnerability identifier: #VU136052
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-59822
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to access connected services exposed through MCP.
The vulnerability exists due to improper access control in the MCP Streamable HTTP endpoint when handling requests with a fabricated Authorization header during OAuth2 passthrough fallback. A remote attacker can send a request with an arbitrary bearer token to access connected services exposed through MCP.
This issue can allow listing and calling configured MCP tools.
Affected software
LiteLLM
How to mitigate CVE-2026-59822
Install security update from vendor's website.
LiteLLM - update to 1.84.0