CVE-2026-84371
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.
Does this matter?
Lower severity and a low EPSS score (0.18%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.18% probability · 8th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security-advisories@github.com
References
- https://github.com/apostrophecms/apostrophe/blob/main/packages/sanitize-html/CHANGELOG.md
- https://github.com/apostrophecms/apostrophe/commit/1135516a1a4a8f9638641c460488a43d8af20081
- https://github.com/apostrophecms/apostrophe/commit/38ff1106c8176b16c2da9872acd9b449adcbb949
- https://github.com/apostrophecms/apostrophe/pull/5552
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-g8qq-57p8-ggw5
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.