CVE-2026-84371

Vulnerability Description

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.

CVSS Score

Related Weaknesses (CWE)

References

• https://github.com/apostrophecms/apostrophe/blob/main/packages/sanitize-html/CHA
• https://github.com/apostrophecms/apostrophe/commit/1135516a1a4a8f9638641c460488a
• https://github.com/apostrophecms/apostrophe/commit/38ff1106c8176b16c2da9872acd9b
• https://github.com/apostrophecms/apostrophe/pull/5552
• https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-g8qq-57p8-g