{"id":"CVE-2026-49468","aliases":["GHSA-4xpc-pv4p-pm3w","PYSEC-2026-388"],"url":"https://o3.security/vulnerability/CVE-2026-49468","summary":"LiteLLM: Authentication Bypass via Host Header Injection","details":"### Impact\n\nA Host-header parsing flaw in the LiteLLM proxy could, under specific conditions, allow unauthenticated access to protected management routes.\n\nThe 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.\n\n**Most deployments are not affected.** The bypass is blocked by any upstream layer that validates or normalizes `Host`, such as:\n\n- a CDN or WAF, such as Cloudflare\n- a reverse proxy with `server_name` allowlists\n- a host-based load balancer\n\n**LiteLLM Cloud customers are not affected.**\n\n### Patches\n\nFixed in **`1.84.0`**. Upgrade to `1.84.0` or later. No configuration change is required.\n\n### Workarounds\n\nIf 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.\n\n### References\n\n- Patched release: [`v1.84.0`](https://github.com/BerriAI/litellm/releases/tag/v1.84.0)\n\n**Discovery Credit**: Le The Thang (KCSC) and Kim Ngoc Chung (One Mount Group)","published":"2026-06-22T20:37:14.494Z","modified":"2026-08-12T03:51:08.920486455Z","cvss":null,"epss":{"score":0.00592,"percentile":0.46483,"asOf":"2026-09-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"litellm","fixedVersion":"1.84.0"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/BerriAI/litellm/releases/tag/v1.84.0"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49468.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-49468"},{"type":"ADVISORY","url":"https://github.com/BerriAI/litellm/security/advisories/GHSA-4xpc-pv4p-pm3w"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49468.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49468"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2491520"},{"type":"PACKAGE","url":"https://github.com/BerriAI/litellm"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-4xpc-pv4p-pm3w"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/litellm/PYSEC-2026-388.yaml"},{"type":"WEB","url":"https://pypi.org/project/litellm"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:08.920486455Z"}}