User Impersonation Affecting litellm package, versions [,1.84.0)
Threat Intelligence
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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-17373069
- published18 Jun 2026
- disclosed16 Jun 2026
- creditLilThawg29
Introduced: 16 Jun 2026
NewCVE-2026-49468 (opens in a new tab)How to fix?
Upgrade litellm to version 1.84.0 or higher.
Overview
litellm is a Library to easily interface with LLM API providers
Affected versions of this package are vulnerable to User Impersonation via manipulation of the Host header during HTTP requests. An attacker can gain unauthorized access to protected management routes by crafting a malicious Host header that causes the authentication layer to evaluate a different route than intended.
Note: This is only exploitable if there is no upstream component (such as a CDN, WAF, reverse proxy with explicit server name allowlists, or host-based load balancer) validating or normalizing the Host header before forwarding requests.
Workaround
This vulnerability can be mitigated by placing the proxy behind an upstream component that validates or normalizes the Host header, or by restricting network access to the proxy listener.