---
id: "CVE-2026-113661"
kind: "vulnerability"
aliases: ["CVE-2026-113661", "GHSA-cv27-6wvh-8x7j"]
title: "ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs"
severity: "medium"
cvss: 5.400000095367432
epss: 0.002630000002682209
exploited: false
status: "open"
category: "package"
products: [{"name": "sanitize-html", "fixed": ["2.18.0"], "affected": "< 2.18.0", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["cms", "cwe-79", "node", "npm", "package", "sanitize-html", "user-generated-html"]
not_affected_if: ["default-config", "meta-not-allowed", "sanitize-html-2.18.0-or-later"]
published_at: "2026-10-20T18:15:33+00:00"
first_seen_at: "2026-10-23T19:11:32+00:00"
updated_at: "2026-10-23T19:58:18+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-cv27-6wvh-8x7j", "first_seen_at": "2026-10-23T19:11:32+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-113661", "first_seen_at": "2026-10-23T21:57:21+00:00"}]
---

# ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs

sanitize-html versions before 2.18.0 keep a meta refresh URL inside the content attribute even when its scheme is javascript: or data:, when an integrator has allowed meta with http-equiv and content. A viewer of the sanitized HTML can be redirected to attacker-chosen URLs or run script, which is stored XSS or open redirect.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- npm:sanitize-html affected < 2.18.0 fixed 2.18.0

## How to check

Run: npm ls sanitize-html
Search your sanitize-html calls for allowedTags or allowedAttributes containing 'meta' together with 'http-equiv' or 'content'.

## Fix

Upgrade sanitize-html to 2.18.0 or later.
If you cannot upgrade yet, remove 'meta' from allowedTags or remove 'content' from the meta allowedAttributes.

## Timeline

- 2026-10-23T19:11:32+00:00 ghsa https://github.com/advisories/GHSA-cv27-6wvh-8x7j
- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-113661

## From the sources

### 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

Local `sanitize-html@2.17.7`. Output inspection only:

```text
node -e '
const sanitize = require("sanitize-html");
const opts = { allowedTags: ["meta"], allowedAttributes: { meta: ["http-equiv", "content"] } };
for (const html of [
  "<meta http-equiv=\"refresh\" content=\"0;url=javascript:alert(1)\">",
  "<meta http-equiv=\"refresh\" content=\"0;url=data:text/html,aaa\">",
  "<form><button formaction=\"javascript:alert(1)\">x</button></form>",
]) {
  console.log(html, "=>", sanitize(html, html.includes("meta") ? opts : { allowedTags: ["form","button"], allowedAttributes: { button: ["formaction"] } }));
}
'
```

Expected: refresh `javascript:` / `data:` remain; 53606 `formaction` is removed. Do not attach a browser hang or stored-XSS page.

### Impact

An integrator who allowed `meta` + `content` expecting `allowedSchemes` to apply (the 53606 configuration pattern) still emits a refresh to `javascript:`, `data:`, or an attacker `https:` URL. Stored XSS / open redirect for viewers of that HTML. Default config is not affected.

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