Vulnerability in Rack
CVE-2026-34763
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.
EPSS: 0.002 (15.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Rack — versions < 2.2.23, >= 3.0.0.beta1, < 3.1.21, >= 3.2.0, < 3.2.6
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34763?
- CVE-2026-34763 is a medium-severity vulnerability in Rack, classified under CWE-625. CVSS score: 5.3/10. Published 2026-04-02.
- How severe is CVE-2026-34763?
- Medium severity. CVSS v3 base score is 5.3 out of 10.