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CVE-2026-49468 — Vulnerability in litellm — CVE Details

CRITICAL

LiteLLM: Authentication Bypass via Host Header Injection

Published June 16, 2026Updated September 10, 2026Source: osv

Summary

### 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 - Patched release: [`v1.84.0`](https://github.com/BerriAI/litellm/releases/tag/v1.84.0) **Discovery Credit**: Le The Thang (KCSC) and Kim Ngoc Chung (One Mount Group)

Advisory Timeline

  • First published June 16, 2026 (118 days ago).
  • Last revised September 10, 2026 — 85 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

pip
Update litellm to 1.84.0 or later
pip install "litellm>=1.84.0"

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Affects 1 ecosystem: pypi (1).

PackageEcosystemAffectedFixed In
litellm
pypi
0.1.0, 0.1.1, 0.1.2, 0.1.201 (+741 more)1.84.0

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.8 score means for each attack dimension.

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently Asked Questions

What is CVE-2026-49468?
LiteLLM: Authentication Bypass via Host Header Injection This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.8/10).
How do I check if my project is affected by CVE-2026-49468?
CVE-2026-49468 affects litellm. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2026-49468 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score
9.8

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-4xpc-pv4p-pm3w
PYSEC-2026-388

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