Vulnerability · Published Jun 12, 2026 · Assigned by GitHub_M
CVE-2026-53606sanitize-html has an incomplete URI scheme validation that allows javascript: URIs through action, formaction, data, poster, and background attributes
Medium 5.4
In plain English
A medium-severity cross-site scripting in sanitize-html from apostrophecms. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | sanitize-html | 2.17.5 | GHSA-vccv-cmxp-4j9h |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| apostrophecms | sanitize-html | < 2.17.5 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N