Sanitizer Bypass Vulnerability in ApostropheCMS by Apostrophe, Affecting sanitize-html
CVE-2026-44990

9.3CRITICAL

Key Information:

Vendor

Apostrophecms

Status
Sanitize-html
Vendor
CVE Published:
12 June 2026

What is CVE-2026-44990?

ApostropheCMS, paired with the sanitize-html library, contains a flaw that allows attackers to exploit the content management system. Undesirable content within a disallowed xmp element can be transformed into executable HTML or JavaScript by certain versions of sanitize-html, specifically those before 2.17.4. This vulnerability occurs due to a sanitizer bypass in the default disallowedTagsMode: 'discard', posing a risk of stored cross-site scripting (XSS) in setups where the sanitized output is rendered visually without adequate filtering. Version 2.17.4 has been released to address this issue.

Affected Version(s)

sanitize-html < 2.17.4

References

https://github.com/apostrophecms/apostrophe/security/advi...
x_refsource_CONFIRM

CVSS V3.1

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.