{"id":"CVE-2026-116883","kind":"vulnerability","aliases":["CVE-2026-116883"],"related":[],"title":"Semantic MediaWiki: schema descriptions allow stored cross-site scripting by editors","description":"Semantic MediaWiki from 3.1.0 before 7.3.1 contains a stored cross-site scripting vulnerability that allows authenticated schema editors to inject HTML through schema descriptions. Attackers with the smw-schemaedit permission can save HTML that is passed unescaped to Html::rawElement() in HtmlBuilder, altering pages and targeting users who view the schema.","summary":"Semantic MediaWiki versions from 3.1.0 before 7.3.1 do not escape schema descriptions, so HTML saved by a user with the smw-schemaedit permission is rendered as-is. Other users who view the schema can have script run in their browser, and the page content can be altered.","severity":"medium","cvss":4.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["mediawiki","package","self-hosted","semantic-mediawiki"],"not_affected_if":["no-schema-editors","version-7.3.1-or-later"],"how_to_check":"- Check the installed Semantic MediaWiki version in Special:Version or in the extension's composer.lock or extension.json.\n- Check whether any users hold the `smw-schemaedit` permission (unknown how to list them from the sources).","fix":"- Upgrade Semantic MediaWiki to `7.3.1` or later.","status":"open","published_at":"2026-10-27T11:17:30+00:00","first_seen_at":"2026-10-27T11:31:27+00:00","triaged_at":"2026-10-27T11:32:15+00:00","updated_at":"2026-10-27T11:32:15+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-27T11:32:15Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Semantic MediaWiki to `7.3.1` or later.","reach":"network","title":"Semantic MediaWiki: schema descriptions allow stored cross-site scripting by editors","impact":"medium","summary":"Semantic MediaWiki versions from 3.1.0 before 7.3.1 do not escape schema descriptions, so HTML saved by a user with the smw-schemaedit permission is rendered as-is. Other users who view the schema can have script run in their browser, and the page content can be altered.","category":"package","nicknames":[],"who_cares":["mediawiki","semantic-mediawiki","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Script runs in other users' browsers and page content is altered","analyst_note":"","how_to_check":"- Check the installed Semantic MediaWiki version in Special:Version or in the extension's composer.lock or extension.json.\n- Check whether any users hold the `smw-schemaedit` permission (unknown how to list them from the sources).","needs_analyst":false,"not_affected_if":["version-7.3.1-or-later","no-schema-editors"],"who_is_affected":"Sites running Semantic MediaWiki from 3.1.0 up to but not including 7.3.1 that use schema editing. Exposure requires an account with the smw-schemaedit permission to save the HTML, and the risk falls on users who view the affected schema. Sites on 7.3.1 or later are not affected.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00061,"input_tokens":3358,"output_tokens":549,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-116883':15A,18A '-2026':14A,17A '3.1.0':31B,79C '7.3.1':33B,81C 'allow':5A,91C 'alter':75B,120C 'as-i':53B 'attack':101C 'authent':92C 'browser':68B 'contain':82C 'content':72B 'cross':8A,86C 'cross-sit':7A,85C 'cve':13A,16A 'descript':4A,38B,100C 'editor':12A,94C 'escap':36B 'host':23B 'html':40B,97C,110C,116C 'htmlbuilder':119C 'inject':96C 'mediawiki':2A,19B,26B,28B,77C 'packag':20B 'page':71B,121C 'pass':113C 'permiss':50B,107C 'rawel':117C 'render':52B 'run':65B 'save':41B,109C 'schema':3A,37B,61B,93C,99C,128C 'schemaedit':49B,106C 'script':10A,64B,88C 'self':22B 'self-host':21B 'semant':1A,25B,27B,76C 'semantic-mediawiki':24B 'site':9A,87C 'smw':48B,105C 'smw-schemaedit':47B,104C 'store':6A,84C 'target':123C 'unescap':114C 'user':44B,57B,124C 'version':29B 'view':59B,126C 'vulner':89C","nicknames":[],"mitigations":[],"who_affected":"Sites running Semantic MediaWiki from 3.1.0 up to but not including 7.3.1 that use schema editing. Exposure requires an account with the smw-schemaedit permission to save the HTML, and the risk falls on users who view the affected schema. Sites on 7.3.1 or later are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T11:17:30+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-116883","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116883","severity":null,"published_at":"2026-10-27T11:17:30+00:00","modified_at":"2026-10-27T11:17:30+00:00","first_seen_at":"2026-10-27T11:31:27+00:00","fetched_at":"2026-10-27T11:31:27+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}