๐Ÿ” CVE Alert

CVE-2026-84371

MEDIUM 5.4

ApostropheCMS: Stored XSS via SVG SMIL URI-list scheme-policy bypass

CVSS Score
5.4
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-79
Vendor apostrophecms
Product apostrophe
Published Sep 1, 2026
Stay Ahead of the Next One

Get instant alerts for apostrophecms apostrophe

Be the first to know when new medium vulnerabilities affecting apostrophecms apostrophe are published โ€” delivered to Slack, Telegram or Discord.

Get Free Alerts โ†’ Free ยท No credit card ยท 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

Affected Versions

apostrophecms / apostrophe
>= 1.9.0, < 2.17.7

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-g8qq-57p8-ggw5 github.com: https://github.com/apostrophecms/apostrophe/pull/5552 github.com: https://github.com/apostrophecms/apostrophe/commit/1135516a1a4a8f9638641c460488a43d8af20081 github.com: https://github.com/apostrophecms/apostrophe/commit/38ff1106c8176b16c2da9872acd9b449adcbb949 github.com: https://github.com/apostrophecms/apostrophe/blob/main/packages/sanitize-html/CHANGELOG.md