CVE-2026-48710

CVE-2026-48710

Name

CVE-2026-48710

Description

Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP `Host` request header was not validated before being used to reconstruct `request.url`. Because the routing algorithm relies on the raw HTTP path while `request.url` is rebuilt from the `Host` header, a malformed header could make `request.url.path` differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on `request.url` (rather than the raw `scope` path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the `Host` header against the grammar of RFC 9112 §3.2 / RFC 3986 §3.2.2 when constructing `request.url` and falls back to `scope["server"]` for malformed values.

NVD Severity

unknown

Other trackers

CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia

Mailing lists

oss-security, full-disclosure, bugtraq

Exploits

Exploit DB, Metasploit

Forges

GitHub (code, issues), Aports (code, issues)

Type	URI
security-advisories@github.com	https://badhost.org
security-advisories@github.com	https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6
security-advisories@github.com	https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr
security-advisories@github.com	https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml
security-advisories@github.com	https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette
security-advisories@github.com	https://www.secwest.net/starlette
security-advisories@github.com	https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette

Type

URI