CVE Catalog

CVE-2026-40186

MediumCVSS 6.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.25%

16th percentile - higher than 16% of all known CVEs

Summary

ApostropheCMS is an open-source Node.js CMS. A regression in commit 49d0bb7, included in version 2.17.1 of the sanitize-html package, bypasses allowedTags enforcement for text inside nonTextTagsArray elements (textarea and option). ApostropheCMS 4.28.0 is affected through its dependency on the vulnerable sanitize-html version. An attacker can inject arbitrary tags including XSS payloads through any allowed option or textarea element using entity encoding. Fixed in sanitize-html 2.17.2 and ApostropheCMS 4.29.0.

Risk Assessment

An attacker could conduct an XSS attack, potentially leading to session theft, account takeover, or other damage. The vulnerability affects configurations where option or textarea are allowed, common in form builders.

Recommendation

Update sanitize-html to version 2.17.2 and ApostropheCMS to version 4.29.0. Additionally, review allowedTags configuration and restrict allowed tags to necessary ones.

Other vulnerabilities in ApostropheCMS

See all
Original NVD description (English source)

ApostropheCMS is an open-source Node.js content management system. A regression introduced in commit 49d0bb7, included in versions 2.17.1 of the ApostropheCMS-maintained sanitize-html package bypasses allowedTags enforcement for text inside nonTextTagsArray elements (textarea and option). ApostropheCMS version 4.28.0 is affected through its dependency on the vulnerable sanitize-html version. The code at packages/sanitize-html/index.js:569-573 incorrectly assumes that htmlparser2 does not decode entities inside these elements and skips escaping, but htmlparser2 10.x does decode entities before passing text to the ontext callback. As a result, entity-encoded HTML is decoded by the parser and then written directly to the output as literal HTML characters, completely bypassing the allowedTags filter. An attacker can inject arbitrary tags including XSS payloads through any allowed option or textarea element using entity encoding. This affects non-default configurations where option or textarea are included in allowedTags, which is common in form builders and CMS platforms. This issue has been fixed in version 2.17.2 of sanitize-html and 4.29.0 of ApostropheCMS.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS