SemanticMediaWiki from 3.2.0 before 7.3.1 contains a stored cross-site scripting vulnerability that allows users with the smw-schemaedit right to inject markup through an unescaped property group schema canonicalname. Attackers can save a schema whose canonicalname holds script markup, which GroupFormatter renders unescaped in Special:Browse headings, executing JavaScript in viewers' sessions including administrators.