CVE-2026-40186 (GCVE-0-2026-40186)

Vulnerability from cvelistv5 – Published: 2026-04-15 20:15 – Updated: 2026-04-16 14:15
VLAI
Title
ApostropheCMS: sanitize-html allowedTags Bypass via Entity-Decoded Text in nonTextTags Elements
Summary
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.
Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-16 14:15 UTC
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8129 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
apostrophecms apostrophe Affected: >= 4.28.0, < 4.29.0
guessed Create a notification for this product.
apostrophecms sanitize-html Affected: >= 2.17.1, < 2.17.2
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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