CVE-2026-42271

HIGH CISA KEV

CVSS v3.1: 8.8 · EPSS: 0.0412 (88.8 percentile) · CISA KEV: Yes

CISA KEVNetworkNo user interactionCommand InjectionOS Command InjectionVendor advisory ref

Source data as of:

At a glance

Severity
HIGH
CVSS
8.8 v3.1 · NVD
EPSS
0.0412 (88.8 percentile) · FIRST.org
CISA KEV
Yes KEV added: 2026-06-08
Type
Command Injection, OS Command Injection · NVD CWE
Attack conditions (CVSS vector)
NetworkNo user interaction · Source: NVD Vector
Affected vendors
litellm
Published
2026-05-08 · Modified: 2026-06-09

CVSS / EPSS / KEV

CVSS v3.1 8.8 / 10 HIGH Source: NVD
CVSS v4.0 8.7 / 10 HIGH Source: NVD
EPSS 0.0412 88.8 percentile Source: FIRST.org
CISA KEV Yes KEV added: 2026-06-08 Source: CISA

Source — CVSS: NVD · EPSS: FIRST.org · KEV: CISA. Data & Sources

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.

Record details

CVE ID
CVE-2026-42271
CVSS (v3.1)
8.8 (HIGH)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore
2.8
Impact subscore
5.9
EPSS
0.0412 (88.8 percentile) — 2026-06-09
CISA KEV
Yes — KEV added: 2026-06-08, Remediation due (CISA): 2026-06-22
Known ransomware use
Unknown
Weakness (CWE)
CWE-77, CWE-78
Affected vendors
litellm
Affected configurations (CPE)
1
Published
2026-05-08
Modified
2026-06-09
Status
Analyzed

References

Reference URLs as listed by NVD, grouped by a mechanical match on the link's host/pattern. Labels describe the link type only.