CVE-2026-25500
Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`).
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
Description
Rack is a modular Ruby web server interface. Prior to versions 2.2.22, 3.1.20, and 3.2.5, `Rack::Directory` generates an HTML directory index where each file entry is rendered as a clickable link. If a file exists on disk whose basename starts with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index contains an anchor whose `href` is exactly `javascript:alert(1)`. Clicking the entry executes JavaScript in the browser (demonstrated with `alert(1)`). Versions 2.2.22, 3.1.20, and 3.2.5 fix the issue.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.22% probability · 13th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- rack/rack
- Source
- security-advisories@github.com
References
- https://github.com/rack/rack/commit/f2f225f297b99fbee3d9f51255d41f601fc40affPatch
- https://github.com/rack/rack/security/advisories/GHSA-whrj-4476-wvmpExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.