CVE-2026-125110— Rack: Rack::Static header_rules bypass via dot-segment normalization mismatch

Quick assessment

Affected

rack rack

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Rack 是一个模块化的 Ruby Web 服务器接口。在 2.2.25、3.1.23 和 3.2.8 版本之前，会在规范化路径后提供该路径的文件，但其却仅针对经过 URL 解码（未进行完整路径规范化）的路径进行评估。因此，未经身份验证的攻击者可以通过原始或百分号编码的“点段”（如）请求已知文件，从而绕过针对特定路径的安全响应头（例如或）并获取该文件。未使用基于路径的的应用不受此问题影响。该问题已在 2.2.25、3.1.23 和 3.2.8 版本中修复。

CVSS 5.3 · Medium Updated Nov 10, 2026

Possible ATT&CK Techniques 2 AI

T1078.001 · Default Accounts T1190 · Exploit Public-Facing Application

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Vulnerability Information

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Vulnerability Title

Rack: Rack::Static header_rules bypass via dot-segment normalization mismatch

Source: CVE Program / CVE List V5

Vulnerability Description

Rack is a modular Ruby web server interface. Prior to 2.2.25, 3.1.23, and 3.2.8, Rack::Static serves a path after Utils.clean_path_info normalization but evaluates header_rules against a path that is only URL-decoded. An unauthenticated attacker can request a known file through raw or percent-encoded dot segments and receive it without path-specific security headers such as Content-Disposition or Content-Security-Policy. Applications that do not use path-specific header_rules are not affected. This issue is fixed in versions 2.2.25, 3.1.23, and 3.2.8.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

不正确的行为次序：规范化之前验证

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
rack	rack	< 2.2.25	-

II. Public POCs for CVE-2026-125110

#	POC Description	Source Link	Shenlong Link

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No public POC found.

III. Intelligence Information for CVE-2026-125110

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Other References for CVE-2026-125110 (4)

https://github.com/rack/rack/security/advisories/GHSA-wvg4-6p58-3gh3 x_refsource_CONFIRM
https://github.com/rack/rack/commit/18a07fe553afb4d8a678d6a948cd6ba1e11e28be x_refsource_MISC
https://github.com/rack/rack/commit/9d7f19484ffd5ed5e032678c26ee6eff96d3a0a3 x_refsource_MISC
https://github.com/rack/rack/commit/e88097ccb88be44d06d47b42daffe04929516ee4 x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-125110

Same Patch Batch · rack · 2026-11-09 · 4 CVEs total

CVE-2026-125111	7.5 HIGH	Rack: Multipart parsing allows DoS via unbounded scan buffer growth
CVE-2026-125109	4.8 MEDIUM	Rack: Rack::Request#host_with_port (and #base_url / #url) return the raw invalid Host head
CVE-2026-125108	3.7 LOW	Rack: Multipart boundary ambiguity guard in Rack::Multipart::Parser can be bypassed with a

IV. Related Vulnerabilities

Same product: rack

Same vendor: rack

Same weakness: CWE-180