GitHub Advisoryadvisory · PyPI

GHSA-xqmj-j6mv-4862 LiteLLM: Server-Side Template Injection in /prompts/test endpoint

HIGH Published 2026-04-24 Modified 2026-05-12 Official page ↗
Aliases
CVE-2026-42203
Ecosystem
PyPI
Packages
litellm
Severity
High
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-1336
Reviewed
2026-04-24

Affected packages

• PyPI litellm: >= 1.80.5, < 1.83.7 → fixed in 1.83.7

Description

Impact The `POST /prompts/test` endpoint accepted user-supplied prompt templates and rendered them without sandboxing. A crafted template could run arbitrary code inside the LiteLLM Proxy process. The endpoint only checks that the caller presents a valid proxy API key, so any authenticated user could reach it. Depending on how the proxy is deployed, this could expose secrets in the process environment (such as provider API keys or database credentials) and allow commands to be run on the host. Proxy deployments running an affected version are in scope. Patches The issue is fixed in `1.83.7-stable`. The fix switches the prompt template renderer to a sandboxed environment that blocks the attributes this attack relies on. LiteLLM recommends upgrading to `1.83.7-stable` or later. Workarounds If upgrading is not immediately possible: 1. Block `POST /prompts/test` at your reverse proxy or API gateway. 2. Review and rotate API keys that should not have access to prompt management routes.

Related

Alias · CVE (1)

  • CVE-2026-42203 LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. vulnerability

Weakness · CWE (1)

  • CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine weakness

References