{"id":"GHSA-hg8h-557g-q8pp","summary":"Semantic MediaWiki vulnerable to stored XSS through wikitext via improper use of non-reserved data attributes","details":"### Summary\nThe SemanticMediaWiki extension inserts the unsanitized value of a data attribute into the DOM as HTML, allowing for stored XSS through wikitext.\n\n### Details\n\nIn `ext.smw.js`, the `data-subtab` attribute of all elements with the `smw-subtab` class is parsed as JSON and appended to the `innerHTML` of the element:\nhttps://github.com/SemanticMediaWiki/SemanticMediaWiki/blob/62f1fa765b626e21d88999b97a3e8029db9fd385/res/smw/ext.smw.js#L37-L42\nHowever, most data attributes (except for reserved ones) like `data-subtab` can be used in wikitext. Therefore, it is possible to insert arbitrary HTML and JS through wikitext.\nThe decoded (`\"` will turn to `"`, but it will be decoded when it is retrieved through `.dataset`) value of the `data-subtab` attribute in the payload is `\"\u003cimg src='' onerror=alert(1)\u003e\"`. This is valid JSON and returns a string with `\u003cimg src='' onerror=alert(1)\u003e` when being decoded.\n\n### PoC\n\n1. Create a page with the following contents:\n```html\n{{#tag:div|\n|class=smw-subtab\n|data-subtab=\"\"\u003cimg src='' onerror=alert(1)\u003e\"\"\n}}\n```\n2. Visit the page\n\n\u003cimg width=\"991\" height=\"465\" alt=\"image\" src=\"https://github.com/user-attachments/assets/5d28d852-72d6-41dc-a59a-faac1610015f\" /\u003e\n\u003cimg width=\"497\" height=\"69\" alt=\"image\" src=\"https://github.com/user-attachments/assets/02309390-0b40-46d9-b690-de8cd25dba59\" /\u003e\n\n### Impact\n\nArbitrary HTML can be inserted into the DOM by any user with the `edit` right, allowing for JavaScript to be executed.","aliases":["CVE-2025-61682"],"modified":"2026-09-18T16:15:09.709078022Z","published":"2026-09-18T16:07:29Z","database_specific":{"nvd_published_at":null,"cwe_ids":["CWE-79"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-09-18T16:07:29Z"},"references":[{"type":"WEB","url":"https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-hg8h-557g-q8pp"},{"type":"PACKAGE","url":"https://github.com/SemanticMediaWiki/SemanticMediaWiki"},{"type":"WEB","url":"https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.0.0"}],"affected":[{"package":{"name":"mediawiki/semantic-media-wiki","ecosystem":"Packagist","purl":"pkg:composer/mediawiki/semantic-media-wiki"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.1.0"},{"fixed":"7.0.0"}]}],"versions":["3.1.0","3.1.1","3.1.2","3.1.3","3.1.4","3.1.5","3.1.6","3.2.0","3.2.0-rc.1","3.2.0-rc.2","3.2.1","3.2.2","3.2.3","4.0.0","4.0.1","4.0.2","4.1.0","4.1.1","4.1.2","4.1.3","4.2.0","5.0.0","5.0.1","5.0.2","5.1.0","6.0.0","6.0.1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-hg8h-557g-q8pp/GHSA-hg8h-557g-q8pp.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"}]}