{"id":"CVE-2026-116891","kind":"vulnerability","aliases":["CVE-2026-116891"],"related":[],"title":"SemanticMediaWiki: reflected XSS in FacetedSearch via cstate parameter","description":"SemanticMediaWiki from 4.2.0 before 7.2.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject HTML via unescaped cstate parameters in Special:FacetedSearch. Attackers can craft URLs with q, a matching crc32 csum or filtered=1, and cstate values that break out of hidden input attributes to execute script in victims' browsers.","summary":"SemanticMediaWiki versions 4.2.0 through 7.2.0 do not escape the cstate parameter on Special:FacetedSearch, so crafted URLs inject HTML. An unauthenticated attacker who gets a victim to open such a link can run script in the victim's browser.","severity":"medium","cvss":6.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["mediawiki","package","self-hosted","semantic-mediawiki"],"not_affected_if":["version-outside-range"],"how_to_check":"- Check the installed SemanticMediaWiki version in the wiki's Special:Version page or the extension's composer or extension.json metadata\n- Look for the Special:FacetedSearch page being used with a cstate parameter","fix":"- Upgrade SemanticMediaWiki to `7.2.1` or later","status":"open","published_at":"2026-10-27T11:17:31+00:00","first_seen_at":"2026-10-27T11:31:27+00:00","triaged_at":"2026-10-27T11:32:01+00:00","updated_at":"2026-10-27T11:32:01+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-27T11:32:01Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade SemanticMediaWiki to `7.2.1` or later","reach":"internet","title":"SemanticMediaWiki: reflected XSS in FacetedSearch via cstate parameter","impact":"medium","summary":"SemanticMediaWiki versions 4.2.0 through 7.2.0 do not escape the cstate parameter on Special:FacetedSearch, so crafted URLs inject HTML. An unauthenticated attacker who gets a victim to open such a link can run script in the victim's browser.","category":"package","nicknames":[],"who_cares":["mediawiki","semantic-mediawiki","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Script runs in victims' browsers on the wiki, enabling session theft or actions as them","analyst_note":"","how_to_check":"- Check the installed SemanticMediaWiki version in the wiki's Special:Version page or the extension's composer or extension.json metadata\n- Look for the Special:FacetedSearch page being used with a cstate parameter","needs_analyst":false,"not_affected_if":["version-outside-range"],"who_is_affected":"Wikis running SemanticMediaWiki from 4.2.0 before 7.2.1 that expose Special:FacetedSearch are exposed. The attack needs a victim to open a crafted link, so public wikis with logged-in editors are the main concern. Wikis on versions outside that range or without the extension can skip it.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00061,"input_tokens":3370,"output_tokens":545,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-116891':11A,14A '-2026':10A,13A '1':101C '4.2.0':25B,64C '7.2.0':27B '7.2.1':66C 'allow':76C 'attack':44B,78C,89C 'attribut':111C 'break':106C 'browser':61B,117C 'contain':67C 'craft':38B,91C 'crc32':97C 'cross':71C 'cross-sit':70C 'cstate':7A,32B,84C,103C 'csum':98C 'cve':9A,12A 'escap':30B 'execut':113C 'facetedsearch':5A,36B,88C 'filter':100C 'get':46B 'hidden':109C 'host':19B 'html':41B,81C 'inject':40B,80C 'input':110C 'link':53B 'match':96C 'mediawiki':15B,22B 'open':50B 'packag':16B 'paramet':8A,33B,85C 'q':94C 'reflect':2A,69C 'run':55B 'script':56B,73C,114C 'self':18B 'self-host':17B 'semant':21B 'semantic-mediawiki':20B 'semanticmediawiki':1A,23B,62C 'site':72C 'special':35B,87C 'unauthent':43B,77C 'unescap':83C 'url':39B,92C 'valu':104C 'version':24B 'via':6A,82C 'victim':48B,59B,116C 'vulner':74C 'xss':3A","nicknames":[],"mitigations":[],"who_affected":"Wikis running SemanticMediaWiki from 4.2.0 before 7.2.1 that expose Special:FacetedSearch are exposed. The attack needs a victim to open a crafted link, so public wikis with logged-in editors are the main concern. Wikis on versions outside that range or without the extension can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T11:17:31+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/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-2026-116891","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116891","severity":null,"published_at":"2026-10-27T11:17:31+00:00","modified_at":"2026-10-27T11:17:31+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"}