High

LiteLLM: Authenticated command execution via MCP stdio test endpoints

  • Disclosed: 25.04.2026
  • Updated: 11.10.2026 15:17

CISA confirms exploitation of this vulnerability in real attacks. Prioritise checking whether your application is affected. CISA KEV · CC0 1.0

Impact

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.

Patches

Fixed in 1.83.7. Both test endpoints now require the PROXY_ADMIN role, bringing them into line with the save endpoint.

Workarounds

If upgrading is not immediately possible, developers should block POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list at their reverse proxy or API gateway.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) litellm >= 1.74.2, < 1.83.7 1.83.7

References

CVSS score 8.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-77, CWE-78
Platform
Python (PyPI)
Package
litellm
Disclosed
25.04.2026
Updated
11.10.2026 15:17

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-2599 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-v4p8-mg3p-g94g - CC BY 4.0

Vulnerability history: litellm

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (42) in the archive
Total entries
42
First → latest
04.2024 09.2026
Without a fix
14
Exploited in attacks
3

Severity breakdown

  • Critical 7
  • High 17
  • Medium 8
  • Low 9
  • Unrated 1

Disclosures per year

  1. 2024: 8
  2. 2025: 6
  3. 2026: 28
Severity:
  1. High Exploited in attacks CVE-2026-59822 < 1.84.0 1.84.0
  2. Critical · 9.8 CVE-2026-49468 < 1.84.0 1.84.0
  3. High · 8.8 CVE-2026-40217 >= 1.81.8, < 1.83.10 1.83.10
  4. LiteLLM: Authenticated command execution via MCP stdio test endpoints this entry
    High · 8.8 Exploited in attacks CVE-2026-42271 >= 1.74.2, < 1.83.7 1.83.7
  5. Critical · 9.8 Exploited in attacks CVE-2026-42208 >= 1.81.16, < 1.83.7 1.83.7
  6. High CVE-2026-42203 >= 1.80.5, < 1.83.7 1.83.7
  7. Critical ghsa-5mg7-485q-xm76 >= 1.82.7, <= 1.82.8 no fix
  8. High · 8.1 CVE-2025-0628 < 1.61.15 1.61.15
  9. High · 7.5 CVE-2025-0330 <= 1.52.1 no fix
  10. High · 7.5 CVE-2024-9606 < 1.44.12 1.44.12
  11. High · 8.8 CVE-2024-6825 >= 1.40.3.dev2, <= 1.40.12 no fix
  12. High · 7.5 CVE-2024-10188 < 1.53.1.dev1 1.53.1.dev1
  13. High · 7.5 CVE-2024-6587 < 1.44.8 1.44.8
  14. Critical · 9.8 CVE-2024-5751 < 1.40.16 1.40.16
  15. High · 6.5 CVE-2024-4888 < 1.35.36 1.35.36
  16. High · 7.2 CVE-2024-4264 <= 1.28.11 no fix

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