ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs
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:
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:
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.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | sanitize-html | < 2.18.0 | 2.18.0 |
References
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-cv27-6wvh-8x7j
- https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
- https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
- https://github.com/apostrophecms/apostrophe
- https://github.com/apostrophecms/apostrophe/releases/tag/sanitize-html@2.18.0
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- npm
- Package
sanitize-html- Disclosed
- 20.10.2026
- Updated
- 22.10.2026 18:07
Sources and licenses
OSV / GitHub Advisory Database - GHSA-cv27-6wvh-8x7j - CC BY 4.0
Vulnerability history: sanitize-html
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 17
- First → latest
- 11.2018 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 1
- Medium 14
- Low 1
Disclosures per year
- 2018: 2
- 2019: 0
- 2020: 1
- 2021: 2
- 2022: 1
- 2023: 0
- 2024: 1
- 2025: 1
- 2026: 9
-
ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs this entry
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