XSS in Starcitizenwiki Mediawiki-Extensions-Embedvideo

CVE-2026-55692

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. Prior to 4.1.0, with the default $wgEmbedVideoRequireConsent configuration enabled, includes/EmbedService/EmbedHtmlFormatter.php places JSON returned through includes/EmbedService/AbstractEmbedService.php into the data-mw-iframeconfig attribute without safely escaping single quotes. Attacker-controlled archiveorg identifiers and wistia or sharepoint URLs accepted by the affected service validators can cause getUrl() output to terminate the attribute and inject event-handler attributes into the generated figure element. A user able to edit a wiki page can store JavaScript that executes in the wiki origin when visitors render the page. This issue is fixed in version 4.1.0.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (42.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-55692: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55692?
CVE-2026-55692 is a high-severity vulnerability in Starcitizenwiki Mediawiki-Extensions-Embedvideo, classified under Cross-site Scripting. CVSS score: 7.5/10. Published 2026-09-15.
How severe is CVE-2026-55692?
High severity. CVSS v3 base score is 7.5 out of 10.