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 algorit…
Summary
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)…
In-depth triage · Auto channel
No in-depth report has been generated yet (DR-003 v2 AI pipeline is under construction).
Affected products
- :
Lint boundary warnings (4)
The following non-blocking warnings were raised during the lint phase of this triage (e.g. reference URLs not yet on the allowlist). They do not affect entry usability and are disclosed for transparency (see DR-002).
-
REF_URL_NOT_ALLOWLISTEDurl not in allowlist: https://badhost.org -
REF_URL_NOT_ALLOWLISTEDurl not in allowlist: https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette -
REF_URL_NOT_ALLOWLISTEDurl not in allowlist: https://www.secwest.net/starlette -
REF_URL_NOT_ALLOWLISTEDurl not in allowlist: https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette
Sources
- NVD DATABASE
Original Links
- https://badhost.org Mitigation
- https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6 Patch
- https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr Vendor Advisory
- https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml Third Party Advisory
- https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette Mitigation
- https://www.secwest.net/starlette Exploit
- https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette Exploit
- https://access.redhat.com/errata/RHSA-2026:22992
- https://access.redhat.com/errata/RHSA-2026:22993
- https://access.redhat.com/errata/RHSA-2026:23346
- https://access.redhat.com/errata/RHSA-2026:24866
- https://access.redhat.com/errata/RHSA-2026:26226
- https://access.redhat.com/errata/RHSA-2026:30088
- https://access.redhat.com/errata/RHSA-2026:30089
- https://access.redhat.com/errata/RHSA-2026:34456
- https://access.redhat.com/errata/RHSA-2026:34526
- https://access.redhat.com/errata/RHSA-2026:34532
- https://access.redhat.com/errata/RHSA-2026:37275
- https://access.redhat.com/security/cve/CVE-2026-48710
- https://bugzilla.redhat.com/show_bug.cgi?id=2481742
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48710.json
Timeline
- nvd_ingest NVD