ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. Prior to sanitize-html 2.18.0, a non-default configuration that allows meta refresh elements and their http-equiv and content attributes can retain unsafe script or redirect destinations embedded in the refresh content value. This issue is fixed in sanitize-html 2.18.0.

Affected: npm: sanitize-html

### Summary

CVE-2026-53606 expanded `allowedSchemesAppliedToAttributes` so named URL attributes (`action`, `formaction`, `data`, `poster`, `background`, later `ping`, `xlink:href`, …) go through `naughtyHref()`. A **URL nested inside `meta` `content`** (`http-equiv=refresh`) is not an attribute name on that list, so the embedded destination is never scheme-checked.

Default `allowedTags` still omit `meta`. Same non-default integrator config as 53606: allow `meta` plus `http-equiv` / `content`.

On **2.17.7**:

```text sanitizeHtml( '<meta http-equiv="refresh" content="0;url=javascript:alert(1)">', { allowedTags: ['meta'], allowedAttributes: { meta: ['http-equiv', 'content'] } } ) // => <meta http-equiv="refresh" content="0;url=javascript:alert(1)" /> ```

`data:text/html,…` and arbitrary `https:` destinations also survive. `formaction="javascript:…"` (53606) is stripped.

Please **Request CVE**. Credit: Finder + Reporter (`adrbogacz`).

### Details

`naughtyHref()` only runs when the attribute name is in `allowedSchemesAppliedToAttributes` (`index.js` ~385). Refresh URLs live in a `content` value of the form `0;url=…`, so the gate never fires. Adding `content` to that list wholesale would break ordinary meta `content` (description, viewport).

**Fix:** when `http-equiv` is `refresh` (case-insensitive), parse the `; url=` destination and run `naughtyHref('meta', url)`. Drop `content` (or the tag) if the URL is rejected. Leave other `meta` `content` values alone.

### PoC…