{"schema":"threatline.record/2","record":{"id":"CVE-2026-55691","aliases":["GHSA-7h5p-637f-jfr7"],"summary":"StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized class passed to template","details":"### Summary\nThe user supplied class value is fed directly into the sprintf call that creates HTML. You can add a quote to escape the class and then inject arbitrary html/javascript to the final output.\n\n### Details\nThe template [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedHtmlFormatter.php#L138) adds a figure with a class that is substituted in. This value is provided to sprintf [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedHtmlFormatter.php#L156), an unescaped version of the class supplied by the user.\n\n```\n$template = <<<HTML\n    <figure class=\"%s\" data-service=\"%s\" %s %s>\n        <div class=\"embedvideo-wrapper\" %s>%s%s%s</div>%s\n    </figure>\nHTML;\n```\n\n### PoC\nNote the double quote immediately following the single quote to escape the class attribute in the template:\n```\n<youtube class='\" onmouseover=\"alert(document.domain)' id=\"dQw4w9WgXcQ\">dQw4w9WgXcQ</youtube>\n```\n\n### Impact\nArbitrary HTML can be inserted into the DOM by any user on any page, allowing for JavaScript to be executed.","categories":["Libraries & packages"],"product":"starcitizenwiki/embedvideo","vendor":"StarCitizenWiki","ecosystem":"composer","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-7h5p-637f-jfr7","source_modified_at":"2026-10-13T20:50:34Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"composer","name":"starcitizenwiki/embedvideo"},"range":"<= 4.0.0"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-55691","source_modified_at":"2026-09-16T15:44:27.031Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"mediawiki-extensions-EmbedVideo","vendor":"StarCitizenWiki","versions":[{"version":"< 4.1.0","status":"affected"}],"defaultStatus":null},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-7h5p-637f-jfr7","source_modified_at":"2026-09-10T03:50:48.730623590Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"Packagist","name":"starcitizenwiki/embedvideo","purl":"pkg:composer/starcitizenwiki/embedvideo"},"ranges":[{"events":[{"introduced":"0"},{"fixed":"4.1.0"}],"type":"ECOSYSTEM"}],"versions":["3.0.0","3.0.1","3.0.2","3.0.3","3.0.4","3.0.5","3.0.6","3.0.7","3.0.8","3.0.9","3.1.0","3.2.0","3.2.1","3.2.2","3.2.3","3.2.4","3.2.5","3.2.6","3.2.7","3.2.8","3.3.0","3.4.0","3.4.1","3.4.2","3.4.3","4.0.0"]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-7h5p-637f-jfr7","source_modified_at":"2026-10-13T20:50:34Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"composer","name":"starcitizenwiki/embedvideo"},"version":"4.1.0"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-7h5p-637f-jfr7","source_modified_at":"2026-09-10T03:50:48.730623590Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"Packagist","name":"starcitizenwiki/embedvideo","purl":"pkg:composer/starcitizenwiki/embedvideo"},"version":"4.1.0"}],"cvss":8.6,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00484,"percentile":0.40799,"score_date":"2026-10-23"},"published_at":"2026-09-15T16:34:59.998Z","modified_at":"2026-10-13T20:50:34Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-7h5p-637f-jfr7","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-13T20:50:34Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-55691","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-09-16T15:44:27.031Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-7h5p-637f-jfr7","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-09-10T03:50:48.730623590Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-55691","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["GitHub Advisory Database","CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-7h5p-637f-jfr7","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/370156335b325bb81d14d89edf0a1f2643d50a84","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/advisories/GHSA-7h5p-637f-jfr7","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"poc","automatable":"yes","technical_impact":"partial","assessed_at":"2026-09-16T15:44:19.616396Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-13T20:50:34Z","content_hash":"272f8a7a89584748ac8251e64309d1dfeb48d414fdce7f5e1396872e4031fbd8"}}