berriai/litellm · Security

LiteLLM has a sandbox escape in custom-code guardrail

GHSA ID
GHSA-wxxx-gvqv-xp7p
CVE ID
CVE-2026-40217
Severity
high
Published
Updated
CVSS
8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v3
8.8 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4
7.5 · CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Description

Impact

The POST /guardrails/test_custom_code endpoint runs user-supplied Python inside a hand-rolled sandbox. The sandbox can be escaped using bytecode-level techniques, allowing arbitrary code execution in the proxy process — which runs as root in the default Docker image.

Reaching the endpoint requires a proxy-admin credential in default configurations.

Patches

Fixed in 1.83.11. The hand-rolled sandbox has been replaced with RestrictedPython. Upgrade to 1.83.11 or later.

Workarounds

If upgrading is not immediately possible, block POST /guardrails/test_custom_code at your reverse proxy or API gateway.

References

CWEs

References