CVE-2026-34835
Rack::Request accepts invalid Host characters, enabling host allowlist bypass
描述
Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Request parses the Host header using an AUTHORITY regular expression that accepts characters not permitted in RFC-compliant hostnames, including /, ?, #, and @. Because req.host returns the full parsed value, applications that validate hosts using naive prefix or suffix checks can be bypassed. This can lead to host header poisoning in applications that use req.host, req.url, or req.base_url for link generation, redirects, or origin validation. This issue has been patched in versions 3.1.21 and 3.2.6.
如何修補 CVE-2026-34835
要修補 CVE-2026-34835,請將受影響套件升級到下列已修補版本。
- —未列出修補版本
- —升級至 3.1.21 或更新版本
CVE-2026-34835 正在被利用嗎?
低 — EPSS 為 0.2%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0
- >= 3.0.0.beta1, < 3.1.21
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |