PT-2026-50152 · Pypi · Litellm

Published

2026-06-16

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Updated

2026-06-16

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CVE-2026-49468

CVSS v4.0

9.5

Critical

VectorAV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Impact

A Host-header parsing flaw in the LiteLLM proxy could, under specific conditions, allow unauthenticated access to protected management routes.
The auth layer derived the effective route from request.url.path in litellm/proxy/auth/auth utils.py::get request route(), which Starlette reconstructs from the Host header. A crafted Host could therefore make the auth gate evaluate a different route from the one FastAPI dispatched.
Most deployments are not affected. The bypass is blocked by any upstream layer that validates or normalizes Host, such as:
  • a CDN or WAF, such as Cloudflare
  • a reverse proxy with server name allowlists
  • a host-based load balancer
LiteLLM Cloud customers are not affected.

Patches

Fixed in 1.84.0. Upgrade to 1.84.0 or later. No configuration change is required.

Workarounds

If upgrading is not immediately possible, place the proxy behind an upstream component that validates or normalizes the Host header before forwarding (a CDN/WAF, a reverse proxy with explicit server name allowlists, or a cloud load balancer with host-based routing rules), or otherwise restrict network access to the proxy listener.

References

Discovery Credit: Le The Thang (KCSC) and Kim Ngoc Chung (One Mount Group)

Fix

Authentication Bypass by Spoofing

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Weakness Enumeration

CWE-290

Related Identifiers

CVE-2026-49468
GHSA-4XPC-PV4P-PM3W

Affected Products

Litellm