GHSA-h3pq-667x-r789
HIGHPlate media plugins has a XSS in media embed element when using custom URL parsers
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
@udecode/plate-mediaReal-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
Impact
Editors that use MediaEmbedElement and pass custom urlParsers to the useMediaState hook may be vulnerable to XSS if a custom parser allows javascript:, data: or vbscript: URLs to be embedded. Editors that do not use urlParsers and instead consume the url property directly may also be vulnerable if the URL is not sanitised.
The default parsers parseTwitterUrl and parseVideoUrl are not affected.
Examples of vulnerable code:
const { embed } = useMediaState({
urlParsers: [
// Custom parser that does not use an allowlist or validate the URL protocol
(url) => ({ url }),
],
});
return (
<iframe
src={embed!.url}
// ...
/>
);
const { url } = useMediaState();
return (
<iframe
// url property used directly from useMediaState() with no sanitisation
src={url}
// ...
/>
);
const { url } = element;
return (
<iframe
// url property used directly from element with no sanitisation
src={url}
// ...
/>
);
Patches
@udecode/plate-media 36.0.10 resolves this issue by only allowing HTTP and HTTPS URLs during parsing. This affects only the embed property returned from useMediaState.
In addition, the url property returned from useMediaState has been renamed to unsafeUrl to indicate that it has not been sanitised. The url property on element is also unsafe, but has not been renamed. If you're using either of these properties directly, you will still need to validate the URL yourself.
Workarounds
Ensure that any custom urlParsers do not allow javascript:, data: or vbscript: URLs to be returned in the url property of their return values.
If url is consumed directly, validate the URL protocol before passing it to the iframe element.
References
How to verify the protocol of a URL: https://stackoverflow.com/a/43467144
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @udecode/plate-media | all versions | 36.0.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @udecode/plate-media. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @udecode/plate-media to 36.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h3pq-667x-r789 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-h3pq-667x-r789 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-h3pq-667x-r789. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-h3pq-667x-r789 in your dependencies?
O3 detects GHSA-h3pq-667x-r789 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.