原文の説明
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.
悪用確認済み（CISA KEV）
- KEV 追加日
- 2026-09-02
- 対応期限（米連邦機関）
- 2026-09-16
- ランサムウェアでの使用
- Unknown
- 必要な対応
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
詳細
- 公開日
- 2026-05-27
- 最終更新
- 2026-10-02
- CVSS ベクター
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N- CWE
- CWE-444
- EPSS（30日以内の悪用確率）
- 70.29% (パーセンタイル 99)
参考資料
- cve.org/CVE-2026-48710
- nvd.nist.gov/vuln/detail/CVE-2026-48710
- github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr
- github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6
- badhost.org
- github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml
- ostif.org/disclosing-the-badhost-vulnerability-in-starlette
- www.secwest.net/starlette
- www.x41-dsec.de/lab/advisories/x41-2026-002-starlette
本製品は NVD API のデータを使用していますが、NVD による承認または認定を受けたものではありません。CVE® は The MITRE Corporation の登録商標です。CVE レコードは CVE Program の利用規約に基づいて使用しています。