CVE-2026-113657
ApostropheCMS sanitize-html: SMIL animation namespace-prefix bypass allows javascript: URI injection (XSS)
ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From sanitize-html 2.17.7 until 2.18.0, an application configuration that permits namespace-prefixed SVG animation elements and the relevant URL-targeting attributes can bypass the SMIL URL protection because prefixed tag names do not match the unprefixed animation-element check. The bypass can rewrite a link destination to an unsafe URI after the sanitized SVG is rendered, with script execution occurring when a user activates the affected link; the default sanitizer configuration is not unconditionally affected. This issue is fixed in sanitize-html 2.18.0.
- Affected
- apostrophecms · apostrophe · sanitize-html
- CVSS v3.1 GITHUB
- 3.7 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N - EPSS
- 0.31% chance of exploitation in the next 30 days, 24th percentile
- Published
- 2026-10-20
Proof-of-concept exploits (1)
CVE references
- apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ceREFERENCE
- apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350REFERENCE
- apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0REFERENCE
- apostrophecms/apostrophe/security/advisories/GHSA-374f-7chj-9948REFERENCE