Improper Neutralization of Special Elements Used in a Template Engine Affecting litellm package, versions [1.80.5,1.83.7)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-LITELLM-16300055
- published26 Apr 2026
- disclosed24 Apr 2026
- creditUnknown
Introduced: 24 Apr 2026
CVE-2026-42203 (opens in a new tab)How to fix?
Upgrade litellm to version 1.83.7 or higher.
Overview
litellm is a Library to easily interface with LLM API providers
Affected versions of this package are vulnerable to Improper Neutralization of Special Elements Used in a Template Engine via the POST /prompts/test endpoint, which accepts user-supplied prompt templates and renders them without sandboxing. An attacker can execute arbitrary code within the server process by submitting a crafted template after authenticating with a valid proxy API key. This may expose sensitive environment variables or allow commands to be executed on the host.
Workaround
- This vulnerability can be mitigated by blocking
POST /prompts/testat your reverse proxy or API gateway, and by reviewing and rotating API keys that should not have access to prompt management routes.