CVE-2026-42271

8.8 HIGH CISA KEV - Actively Exploited
Published: May 08, 2026 Modified: June 09, 2026
View on NVD

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/BerriAI/litellm/releases/tag/v1.83.7-stable
Source: security-advisories@github.com
Product Release Notes
https://github.com/BerriAI/litellm/security/advisories/GHSA-v4p8-mg3p-g94g
Source: security-advisories@github.com
Mitigation Patch Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-42271
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
US Government Resource

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
8.8 / 10.0
EPSS (Exploit Probability)
4.1%
89th percentile
Exploitation Status
Actively Exploited
Remediation due: 2026-06-22

Weaknesses (CWE)

Affected Vendors

litellm