Star Citizen EmbedVideo Extension Stored XSS through wikitext caused by usage of non-reserved data attributes
Summary
The EmbedVideo extension allows adding arbitrary attributes to an HTML element, allowing for stored XSS through wikitext.
Details
The attributes of an iframe are populated with the value of an unreserved data attribute (data-iframeconfig) that can be set via wikitext:
https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/440fb331a84b2050f4cc084c1d31d58a1d1c202d/resources/ext.embedVideo.videolink.js#L5-L20
Similar code is also present here:
https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/440fb331a84b2050f4cc084c1d31d58a1d1c202d/resources/modules/iframe.js#L139-L155
It is possible to execute JS through attributes like onload or onmouseenter.
PoC
- Create a page with the following contents:
<div class="embedvideo-evl" data-iframeconfig='{"onload": "alert(1)"}'>Click me!</div>
<evlplayer></evlplayer>- Click on the "Click me!" text
- Click on the "Load video" button below <img width="855" height="404" alt="image" src="https://github.com/user-attachments/assets/afb3839a-012c-4e90-a208-a6137b704ccd" />
Impact
Arbitrary HTML can be inserted into the DOM by any user, allowing for JavaScript to be executed.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | starcitizenwiki/embedvideo | <= 4.0.0 | no fix |
References
- https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-4j5h-mvj3-m48v
- https://nvd.nist.gov/vuln/detail/CVE-2025-59839
- https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/4e075d3dc9a15a3ee53f449a684d5ab847e52f01
- https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo
- https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/440fb331a84b2050f4cc084c1d31d58a1d1c202d/resources/ext.embedVideo.videolink.js#L5-L20
- https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/440fb331a84b2050f4cc084c1d31d58a1d1c202d/resources/modules/iframe.js#L139-L155
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L- Weakness (CWE)
CWE-79- Platform
- Composer
- Package
starcitizenwiki/embedvideo- Disclosed
- 24.09.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4j5h-mvj3-m48v - CC BY 4.0
Vulnerability history: starcitizenwiki/embedvideo
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 5
- First → latest
- 09.2025 09.2026
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 5
Disclosures per year
- 2025: 1
- 2026: 4
-
Star Citizen EmbedVideo Extension Stored XSS through wikitext caused by usage of non-reserved data attributes this entry
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