Vulnerability · Published Oct 20, 2026 · Assigned by GitHub_M

CVE-2026-113650ApostropheCMS sanitize-html: unbounded recursion when re-sanitizing the fallback of a discarded iframe (stack overflow, nestingLimit not enforced)

Medium 5.3

In plain English

A medium-severity security flaw in apostrophe from apostrophecms. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.5%top 58.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

ApostropheCMS is an open-source Node.js content management system. In sanitize-html 2.18.0, when an <iframe> is not allowed and disallowedTagsMode is 'discard' (the defaults), its raw-text content is re-sanitized by a recursive call to sanitizeHtml(text, options). The recursion has no bound and starts each nested call with a fresh state. This vulnerability is fixed in 2.18.1.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	sanitize-html	2.18.1	GHSA-c9rx-x947-fp3h

Affected products (as reported)

Vendor	Product	Versions
apostrophecms	apostrophe	< 4.34.0
apostrophecms	sanitize-html	>= 2.18.0, < 2.18.1

Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-c9rx-x947-fp3h x_refsource_CONFIRM
https://github.com/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c32dccd7e505ad5ddf498 x_refsource_MISC
https://github.com/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029b8ce7668634265cfe5ea x_refsource_MISC
https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.1 x_refsource_MISC