CVE-2026-49468: LiteLLM: Authentication Bypass via Host Header Injection
(updated )
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_nameallowlists - a host-based load balancer
LiteLLM Cloud customers are not affected.
References
- access.redhat.com/security/cve/CVE-2026-49468
- bugzilla.redhat.com/show_bug.cgi?id=2491520
- github.com/BerriAI/litellm
- github.com/BerriAI/litellm/releases/tag/v1.84.0
- github.com/BerriAI/litellm/security/advisories/GHSA-4xpc-pv4p-pm3w
- github.com/advisories/GHSA-4xpc-pv4p-pm3w
- github.com/pypa/advisory-database/tree/main/vulns/litellm/PYSEC-2026-388.yaml
- nvd.nist.gov/vuln/detail/CVE-2026-49468
- pypi.org/project/litellm
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49468.json
Code Behaviors & Features
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