CVE-2026-34763
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk15th percentile - higher than 15% of all known CVEs
Summary
Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If the 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.
Risk Assessment
An attacker can gain information about the server's filesystem structure, which may facilitate further attacks and compromise data confidentiality.
Recommendation
Upgrade Rack to versions 2.2.23, 3.1.21, or 3.2.6, which contain the fix.
Original NVD description (English source)
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.