CVE-2026-34831
Rack has Content-Length mismatch in Rack::Files error responses
描述
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Files#fail sets the Content-Length response header using String#size instead of String#bytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the number of bytes actually sent on the wire. Because Rack::Files reflects the requested path in 404 responses, an attacker can trigger this mismatch by requesting a non-existent path containing percent-encoded UTF-8 characters. This results in incorrect HTTP response framing and may cause response desynchronization in deployments that rely on the incorrect Content-Length value. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
如何修補 CVE-2026-34831
要修補 CVE-2026-34831,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 2.2.23 或更新版本
CVE-2026-34831 正在被利用嗎?
低 — EPSS 為 0.1%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- from 0
- from 0, < 2.2.23
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 |