Rack · Rack · CVE-2026-34763
Name of the Vulnerable Software and Affected Versions
Rack versions prior to 2.2.23, 3.1.21, and 3.2.6
Description
Rack::Directory interpolates the configured `root` path directly into a regular expression when deriving the displayed directory path. If the `root` path 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 can expose internal deployment details such as directory layout, usernames, mount points, or naming conventions. The issue occurs because the configured path is inserted directly into a regular expression without escaping.
Recommendations
Update to Rack version 2.2.23 or later.
Update to Rack version 3.1.21 or later.
Update to Rack version 3.2.6 or later.