CVE-2026-25500
mediumpriority · track · 0EPSS 0.003 · 19 %ileDEEUFRRUUSEPSS · scored 2026-10-27
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixedruby4.0-rubygem-rack-2.2-0:2.2.22-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedruby4.0-rubygem-rack-2.2-0:2.2.22-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedruby4.0-rubygem-rack-2.2-0:2.2.22-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedruby4.0-rubygem-rack-2.2-0:2.2.22-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (20)
Products and version ranges known to be affected.
advisories (4)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0881IBM License Metric Tool: Mehrere SchwachstellenDeutsch2026-03-25csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM License Metric Tool ausnutzen, um Informationen offenzulegen, einen Cross Site Scripting Angriff durchzuführen oder einen Denial of Service zu verursachen.
- openSUSE-SU-2026:10286-1ruby4.0-rubygem-rack-2.2-2.2.22-1.1 on GA media2026-03-04csaf · suse_csafDE
ruby4.0-rubygem-rack-2.2-2.2.22-1.1 on GA media
- GHSA-whrj-4476-wvmpStored XSS in Rack::Directory via javascript: filenames rendered into anchor href2026-02-17ghsa · osvUS
## Summary `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 begins with the `javascript:` scheme (e.g. `javascript:alert(1)`), the generated index includes an anchor whose `href` attribute is exactly `javascript:alert(1)`. Clicking this entry executes arbitrary JavaScript in the context of the hosting application. This results in a client-side XSS condition in directory listings generated by `Rack::Directory`. ## Details `Rack::Directory` renders directory entries using an HTML row template similar to: ```html <a href='%s'>%s</a> ``` The `%s` placeholder is populated directly with the file’s basename. If the basename begins with `javascript:`, the resulting HTML contains an executable JavaScript URL: ```html <a href='javascript:alert(1)'>javascript:alert(1)</a> ``` Because the value is inserted directly into the `href` attribute without scheme validation or normalization, browsers interpret it as a JavaScript URI. When a user clicks the link, the JavaScript executes in the origin of the Rack application. ## Impact If `Rack::Directory` is used to expose filesystem contents over HTTP, an attacker who can create or upload files within that directory may introduce a malicious filename beginning with `javascript:`. When a user visits the directory listing and clicks the entry, arbitrary JavaScript executes in the application's origin. Exploitation requires user interaction (clicking the malicious entry). ## Mitigation * Update to a patched version of Rack in which `Rack::Directory` prefixes generated anchors with a relative path indicator (e.g. `./filename`). * Avoid exposing user-controlled directories via `Rack::Directory`. * Apply a strict Content Security Policy (CSP) to reduce impact of potential client-side execution issues. * Where feasible, restrict or sanitize uploaded filenames to disallow dangerous URI scheme prefixes. HackerOne profile: https://hackerone.com/thesmartshadow GitHub account owner: Ali Firas (@thesmartshadow)
- CERTFR-2026-AVI-1352Multiples vulnérabilités dans Oracle PeopleSoftFrançais2026-10-21vendor · certfrFR
also known as (4)
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sources
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references (8)
External citations — patches, advisories, analysis.
- https://github.com/rack/rack/commit/f2f225f297b99fbee3d9f51255d41f601fc40affcnnvd
- https://github.com/rack/rack/releasesPatchcnnvd
- https://github.com/rack/rack/security/advisories/GHSA-whrj-4476-wvmpcnnvd
- https://vigilance.fr/vulnerability/Rack-Cross-Site-Scripting-via-Rack-Directory-Javascript-Filename-49846cnnvd
- https://github.com/rack/rack/commit/f2f225f297b99fbee3d9f51255d41f601fc40affenisa_euvd
- https://github.com/rack/rack/security/advisories/GHSA-whrj-4476-wvmpenisa_euvd
- https://github.com/rack/rack/commit/f2f225f297b99fbee3d9f51255d41f601fc40affPatchnvd
- https://github.com/rack/rack/security/advisories/GHSA-whrj-4476-wvmpExploitMitigationVendor Advisorynvd
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