{"id":"CVE-2026-55691","summary":"EmbedVideo Extension : Stored XSS via unsanitized class passed to template","details":"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, EmbedHtmlFormatter::toHtml in includes/EmbedService/EmbedHtmlFormatter.php passes the user-supplied class value directly to sprintf while constructing a figure element. A quote in the class value can terminate the class attribute and inject arbitrary HTML attributes or markup into the rendered page. A user able to edit a wiki page can store JavaScript that executes for visitors who render the affected content. This issue is fixed in version 4.1.0.","aliases":["GHSA-7h5p-637f-jfr7"],"modified":"2026-09-18T03:30:31.432864400Z","published":"2026-09-15T16:34:59.998Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55691.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-79"]},"references":[{"type":"WEB","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55691.json"},{"type":"ADVISORY","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55691"},{"type":"FIX","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/starcitizenwiki/mediawiki-extensions-embedvideo","events":[{"introduced":"0"},{"fixed":"370156335b325bb81d14d89edf0a1f2643d50a84"},{"fixed":"6982ef6e10a8327a6ecc97eb036f4eb531a6f830"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"4.1.0"}]}}],"versions":["v4.0.0","v3.1.0","v3.0.0","v2.9.0","v2.8.0","v2.7.4","v2.7.3","v2.7.2","2.7.2","v2.7.1","v2.7.0","v2.6.1","v2.6.0","v2.5.2","v2.5.0","v2.4.1","v2.4.0","v2.3.3","v2.3.2","v2.3.1","v2.3.0","v2.2.9","v2.2.8","v2.2.7","v2.2.6","v2.2.5","v2.2.4","v2.2.3","v2.2.2","v2.2.1","v2.2.0","v2.1.8","v2.1.7","v2.1.6","v2.1.5","v2.1.4","v2.1.3","v2.1.2","v2.1","v2.1alpha1","v2.0","v2.0beta3","v2.0beta2","v2.0beta1","v1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55691.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L"}]}