{"id":"CVE-2026-55690","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-55690","summary":"StarCitizenWiki Extension Embed Video: Stored XSS via unsanitized service name in exception text","details":"### Summary\nWhen passing an unknown service name to embedvideo, an error message is rendered containing the invalid service name. The service name is not sanitized and can contain HTML.\n\n### Details\nThere is a hardcoded list of allowed services in a switch statement inside `EmbedServiceFactory#newFromName` [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedServiceFactory.php#L105). When the service name is not known, an exception is thrown with the service name injected into the message via sprintf [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedService/EmbedServiceFactory.php#L286). This message is not sanitized and is marked as isHtml [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedVideo.php#L303-L311). Similarly with `{{evl:` [here](https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/blob/a573a16d925ee0ea0d34b360856dc8ab0b88f822/includes/EmbedVideo.php#L177-L183).\n\n### PoC\n```\n// Must be on a page, not on ExpandTemplates\n{{#ev:<img src=x onerror=alert(document.domain)>|dQw4w9WgXcQ}}\n{{#evl:id=dummy|service=<img src=x onerror=alert(document.domain)>}}\n```\n\n### Impact\nStored XSS that allows arbitrary Javascript/HTML insertion on any page that a user can edit.  It requires no interaction and executes in the wiki origin for every visitor to the page.","published":"2026-06-19T21:14:15Z","modified":"2026-06-19T21:30:11.516796395Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"starcitizenwiki/embedvideo","fixedVersion":"4.1.0"}],"fix":{"url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/9215564bf28a0ceb40be550a55ab78efc0accc56","label":"StarCitizenWiki/mediawiki-extensions-EmbedVideo@9215564"},"references":[{"type":"WEB","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/security/advisories/GHSA-c29q-5xm7-5p62"},{"type":"WEB","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/commit/9215564bf28a0ceb40be550a55ab78efc0accc56"},{"type":"PACKAGE","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo"},{"type":"WEB","url":"https://github.com/StarCitizenWiki/mediawiki-extensions-EmbedVideo/releases/tag/v4.1.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-06-19T21:30:11.516796395Z"}}