CVE-2026-84371
MediumCVSS 5.4Summary
In ApostropheCMS (Node.js CMS) and the sanitize-html library (from version 1.9.0 to 2.17.7), there is a vulnerability in the sanitize-html package where the validation of the animation value attribute does not recognize that attributeName selecting href or xlink:href gives the sibling values from, to, or by SVG SMIL URL semantics. In configurations that allow animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.
Risk Assessment
Users may be exposed to script execution in the application's origin (stored XSS), potentially leading to data theft, session hijacking, or other malicious actions.
Recommendation
Update sanitize-html to version 2.17.7 or later, and if using ApostropheCMS, update it to a version containing the fix.
Other vulnerabilities in sanitize-html
See all- CVE-2026-44990Critical
Vulnerability in sanitize-html library (versions prior to 2.17.4) in default configuration allows bypassing sanitization and injecting HTML/JavaScript via the <xmp> element. This can lead to stored XSS in applications rendering sanitized output.
- CVE-2026-53606Medium
ApostropheCMS, an open-source Node.js content management system, has a vulnerability in sanitize-html that allows dangerous URI schemes like 'javascript:' to pass through in HTML attributes. Versions prior to 2.17.5 do not block these schemes, leading to potential XSS attacks.
Original NVD description (English source)
ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.