Rack 2.2.22 / 3.1.20 / 3.2.5 Fixed XSS in Directory Index via javascript: links
CVE-2026-25500 Published on February 18, 2026
Rack's Stored XSS in Rack::Directory via javascript: filenames rendered into anchor href
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.
Vulnerability Analysis
CVE-2026-25500 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a XSS Vulnerability?
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
CVE-2026-25500 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-25500
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Affected Versions
rack:- Version < 2.2.22 is affected.
- Version >= 3.0.0.beta1, < 3.1.20 is affected.
- Version >= 3.2.0, < 3.2.5 is affected.
Vulnerable Packages
The following package name and versions may be associated with CVE-2026-25500
| Package Manager | Vulnerable Package | Versions | Fixed In |
|---|---|---|---|
| rubygems | rack | < 2.2.22 | 2.2.22 |
| rubygems | rack | >= 3.0.0.beta1, < 3.1.20 | 3.1.20 |
| rubygems | rack | >= 3.2.0, < 3.2.5 | 3.2.5 |
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.