What’s Vulnerable › Vulnerabilities

CVE-2026-55690: EmbedVideo Extension: Stored XSS via unsanitized service name in exception text

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-15 · updated 2026-09-30
• Weakness: CWE-79

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. Prior to 4.1.0, EmbedServiceFactory::newFromName in includes/EmbedService/EmbedServiceFactory.php interpolates an attacker-controlled unknown service name into exception text, and includes/EmbedVideo.php returns that text as HTML through the isHtml output path without neutralization. Both the #ev parser function and the evl parser form can reach this error path. A user able to edit a wiki page can inject stored HTML or JavaScript into the error output, causing code to execute in the wiki origin for visitors who render the page. This issue is fixed in version 4.1.0.

Affected products

• StarCitizenWiki mediawiki-extensions-EmbedVideo: before 4.1.0

References

• https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/9215564bf28a0ceb40be550a55ab78efc0accc56
• https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0
• https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-c29q-5xm7-5p62

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