Improper Neutralization of Special Elements Used in a Template Engine Affecting litellm package, versions [1.80.5,1.83.7)
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Test your applications- Snyk IDSNYK-PYTHON-LITELLM-16300055
- published26 Apr 2026
- disclosed24 Apr 2026
- creditUnknown
Introduced: 24 Apr 2026
NewCVE-2026-42203 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
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.