CVE-2025-59839 Star Citizen EmbedVideo Extension Stored XSS through wikitext caused by usage of non-reserved data attributes
Stored XSS in MediaWiki EmbedVideo extension allows attackers to inject scripts via wikitext, potentially compromising user sessions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-59839?
CVE-2025-59839 is a high-severity cross-site scripting vulnerability in StarCitizenWiki mediawiki-extensions-EmbedVideo, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. In versions 4.0.0 and prior, the EmbedVideo extension allows adding arbitrary attributes to an HTML element, allowing for stored XSS through wikitext. This issue has been patched via commit 4e075d3.
Weakness: CWE-79
Which versions are affected by CVE-2025-59839?
2 open source packages ship an affected version, including starcitizenwiki/embedvideo. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
starcitizenwiki/embedvideo Packagist | All versions to 4.0.0 | None |
starcitizenwiki/embedvideo Packagist | All versions to 4.0.0 | None |
Products include Star-Citizen Embedvideo.
How do I fix CVE-2025-59839?
No fix has been published for CVE-2025-59839 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-59839 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59839 exists.
Sources
Also known as GHSA-4j5h-mvj3-m48v.