CVE-2026-113661 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in sanitize-html. A fix is available for sanitize-html — see the affected versions and patch details below.
ApostropheCMS: Incomplete CVE-2026-53606: `meta http-equiv=refresh` `content` still ships `javascript:` / `data:` URLs
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-113661.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-113661 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
sanitize-htmlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
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 [email protected]. 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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | sanitize-html | all versions | 2.18.0npm install sanitize-html@2.18.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sanitize-html, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sanitize-html to 2.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-113661 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2026-113661 in your dependencies?
Find it across npm, including transitive dependencies.