Low severity · published Oct 20, 2026
CVE-2026-113657
ApostropheCMS sanitize-html: SMIL animation namespace-prefix bypass allows javascript: URI injection (XSS)
3.7
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AP
apostrophe · apostrophecms
< 4.33.0 · source: vendor
SA
sanitize-html · apostrophecms
>= 2.17.7, < 2.18.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-113657
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113657
github.com
https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
github.com
https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
github.com
https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0
github.com
https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-374f-7chj-9948
More from apostrophe
9.1
CVE-2026-53609
Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass
8.7
CVE-2026-35569
ApostropheCMS: Stored XSS in SEO Fields Leads to Authenticated API Data Exposure in ApostropheCMS
8.1
CVE-2026-45013
Apostrophe has a Weak Password Recovery Mechanism for Forgotten Password and Improper Input Validation
8.1
CVE-2026-32730
ApostropheCMS MFA/TOTP Bypass via Incorrect MongoDB Query in Bearer Token Middleware
7.6
CVE-2026-45012
Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget