Answer in brief
CVE-2026-84371 records a Medium severity (CVSS 5.4) vulnerability in ApostropheCMS: Stored XSS via SVG SMIL URI-list scheme-policy bypass. The current sources do not mark it as known exploited. The current feed maps apostrophecms/apostrophe (generic), sanitize-html (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps apostrophecms/apostrophe (generic), sanitize-html (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| apostrophecms/apostrophegeneric | >= 1.9.0, < 2.17.7 | Not reported |
| sanitize-htmlnpm | >=1.9.0,<=2.17.6 | 2.17.7 |
Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
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.
Quoted source text, attributed separately from HOL analysis.