Arbitrary Cmd Exec via /mcp-rest/test/* in LiteLLM 1.74.2-<1.83.7
CVE-2026-42271 Published on May 8, 2026
LiteLLM: Authenticated command execution via MCP stdio test endpoints
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list accepted a full server configuration in the request body, including the command, args, and env fields used by the stdio transport. When called with a stdio configuration, the endpoints attempted to connect, which spawned the supplied command as a subprocess on the proxy host with the privileges of the proxy process. The endpoints were gated only by a valid proxy API key, with no role check. Any authenticated user including holders of low-privilege internal-user keys could therefore run arbitrary commands on the host. This issue has been patched in version 1.83.7.
Known Exploited Vulnerability
This BerriAI LiteLLM Command Injection Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. BerriAI LiteLLM contains a command injection vulnerability that could allow any authenticated user, including holders of low-privilege internal-user keys, to run arbitrary commands on the host.
The following remediation steps are recommended / required by June 22, 2026: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Weakness Types
What is a Command Injection Vulnerability?
The software constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
CVE-2026-42271 has been classified to as a Command Injection vulnerability or weakness.
What is a Shell injection Vulnerability?
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
CVE-2026-42271 has been classified to as a Shell injection vulnerability or weakness.
Affected Versions
BerriAI litellm Version >= 1.74.2, < 1.83.7 is affected by CVE-2026-42271Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.