CVE-2026-53606: apostrophecms sanitize-html Cross-site Scripting

Vulnerability summary

CVE-2026-53606 is a medium (CVSS 5.4) Cross-site Scripting vulnerability in apostrophecms sanitize-html. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities.

Timeline

1. 12-06-2026
   PublishedVulnerability first disclosed.
2. 15-06-2026
   Last modifiedVulnerability information updated.

Description

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Versions of sanitize-html prior to 2.17.5 use `allowedSchemesAppliedToAttributes` (default: `['href', 'src', 'cite']`) to gate the `naughtyHref()` function that blocks dangerous URI schemes like `javascript:` and `vbscript:`. The HTML specification defines 10+ attributes that accept URIs (`action`, `formaction`, `data`, `poster`, `background`, `ping`, `xlink:href`, `dynsrc`, `lowsrc`), but none of these are included in the default gate list. When a developer allows any of these attributes in their configuration, `javascript:` URIs pass through completely unmodified, enabling XSS. Version 2.17.5 patches the issue.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.