CVE-2026-34763

Rack: Rack::Directory info disclosure and DoS via unescaped regex interpolation

State: Published
Severity: 5.3 Medium
Published: Apr 2, 2026
Updated: Apr 2, 2026
Reserved: Mar 30, 2026

Description

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, *, or ., the prefix stripping can fail and the generated directory listing may expose the full filesystem path in the HTML output. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

Scores

CVSS	Score	Vector	Source
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N	GitHub_M

Weaknesses

CWE-625 Permissive Regular Expression

Affected Products

Product	Versions
rackrack	< 2.2.23Affected >= 3.0.0.beta1, < 3.1.21Affected >= 3.2.0, < 3.2.6Affected

References

https://github.com/rack/rack/security/advisories/GHSA-7mqq-6cf9-v2qp

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