{"id":"CVE-2026-55691","state":"PUBLISHED","title":"EmbedVideo Extension : Stored XSS via unsanitized class passed to template","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, 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.","publishedAt":"2026-09-15T16:34:59.998Z","updatedAt":"2026-09-16T15:44:27.031Z","severity":{"score":8.6,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["StarCitizenWiki mediawiki-extensions-EmbedVideo"],"affected":[{"vendor":"StarCitizenWiki","product":"mediawiki-extensions-EmbedVideo","versions":[{"version":"< 4.1.0","status":"affected"}]}],"references":["https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7","https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84","https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55691.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55691","state":"PUBLISHED","datePublished":"2026-09-15T16:34:59.998Z","dateUpdated":"2026-09-16T15:44:27.031Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-17T00:13:10.650Z"},"containers":{"cna":{"title":"EmbedVideo Extension : Stored XSS via unsanitized class passed to template","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"StarCitizenWiki","product":"mediawiki-extensions-EmbedVideo","versions":[{"version":"< 4.1.0","status":"affected"}]}],"references":[{"url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7","name":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84","name":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84","tags":["x_refsource_MISC"]},{"url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0","name":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":8.6,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-15T16:34:59.998Z"},"source":{"advisory":"GHSA-7h5p-637f-jfr7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T15:44:19.616396Z","id":"CVE-2026-55691","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T15:44:27.031Z"}}]}}}