{"id":"CVE-2026-96047","kind":"vulnerability","aliases":["CVE-2026-96047"],"related":[],"title":"Windows Installer: use-after-free lets local user gain higher privileges","description":"Use after free in Windows Installer allows an authorized attacker to elevate privileges locally.","summary":"A use-after-free bug in Windows Installer lets an authorized local user escalate their privileges on the machine. An attacker who already has a foothold on a Windows system could gain administrator-level control.","severity":"high","cvss":7.0,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Windows Installer","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["infrastructure","windows","windows-installer"],"not_affected_if":["no-local-untrusted-users"],"how_to_check":"unknown: the Microsoft Security Update Guide entry for CVE-2026-96047 could not be read (JavaScript-only page). Check that entry for the affected builds and KB, then compare with the installed build (winver, or Get-HotFix).","fix":null,"status":"open","published_at":"2026-11-10T19:22:01+00:00","first_seen_at":"2026-11-10T19:25:28+00:00","triaged_at":"2026-11-10T19:49:28+00:00","updated_at":"2026-11-10T20:02:11+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-11-10T19:49:28Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows Installer: use-after-free lets local user gain higher privileges","impact":"high","summary":"A use-after-free bug in Windows Installer lets an authorized local user escalate their privileges on the machine. An attacker who already has a foothold on a Windows system could gain administrator-level control.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","windows-installer"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"local user gains administrator or SYSTEM privileges on the machine","analyst_note":"Check the Microsoft Security Update Guide entry for affected Windows builds, the patched KB or version, and whether a fix has shipped.","how_to_check":"unknown","plain_action":"","product_name":"Windows Installer","needs_analyst":true,"not_affected_if":["no-local-untrusted-users"],"who_is_affected":"Windows systems where a local user account can run the Windows Installer service; the sources do not list affected Windows builds or whether a patch is out. Attacker needs a valid local account first, so shared multi-user machines and servers with many local users carry more risk.","user_interaction":"unknown","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000681,"input_tokens":4474,"output_tokens":467,"severity_before":"high"},"analyst_status":"done","analyst_note":"Check the Microsoft Security Update Guide entry for affected Windows builds, the patched KB or version, and whether a fix has shipped.","search":"'-2026':14A,17A '-96047':15A,18A 'administr':60B 'administrator-level':59B 'allow':69C 'alreadi':49B 'attack':47B,72C 'author':37B,71C 'bug':31B 'control':62B 'could':57B 'cve':13A,16A 'elev':74C 'escal':40B 'foothold':52B 'free':6A,30B,65C 'gain':10A,58B 'higher':11A 'infrastructur':21B 'instal':2A,25B,34B,68C 'installer':20A 'let':7A,35B 'level':61B 'local':8A,38B,76C 'machin':45B 'privileg':12A,42B,75C 'system':56B 'use':4A,28B,63C 'use-after-fre':3A,27B 'user':9A,39B 'window':1A,22B,24B,33B,55B,67C 'windows':19A 'windows-instal':23B","nicknames":[],"mitigations":[],"who_affected":"Windows systems where a local user account can run the Windows Installer service; the sources do not list affected Windows builds or whether a patch is out. Attacker needs a valid local account first, so shared multi-user machines and servers with many local users carry more risk.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":["installer","windowsinstaller"],"ptokens":["installer","windows"],"labels":["high","infrastructure","vendor","windows","windowsinstaller"],"campaign_type":null,"search_a":"'-2026':14A,17A '-96047':15A,18A 'cve':13A,16A 'free':6A 'gain':10A 'higher':11A 'instal':2A 'installer':20A 'let':7A 'local':8A 'privileg':12A 'use':4A 'use-after-fre':3A 'user':9A 'window':1A 'windows':19A","search_b":"'administr':60B 'administrator-level':59B 'alreadi':49B 'attack':47B 'author':37B 'bug':31B 'control':62B 'could':57B 'escal':40B 'foothold':52B 'free':30B 'gain':58B 'infrastructur':21B 'instal':25B,34B 'let':35B 'level':61B 'local':38B 'machin':45B 'privileg':42B 'system':56B 'use':28B 'use-after-fre':27B 'user':39B 'window':22B,24B,33B,55B 'windows-instal':23B","search_c":"'allow':69C 'attack':72C 'author':71C 'elev':74C 'free':65C 'instal':68C 'local':76C 'privileg':75C 'use':63C 'window':67C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:22:01+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-96047","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-96047","severity":null,"published_at":"2026-11-10T19:22:01+00:00","modified_at":"2026-11-10T19:22:01+00:00","first_seen_at":"2026-11-10T19:25:28+00:00","fetched_at":"2026-11-10T19:25:28+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-96047:2595","url":null,"severity":null,"published_at":"2026-11-10T20:02:11+00:00","modified_at":"2026-11-10T20:02:11+00:00","first_seen_at":"2026-11-10T20:02:11+00:00","fetched_at":"2026-11-10T20:02:11+00:00","note":"MSRC page and CVRF API returned nothing readable; search found only the unrelated Windows Installer CVE-2026-70347 (August). No primary source for this CVE, so no fix, versions or verified fields. CVSS 7.0 AV:L/AC:H/PR:L from Microsoft; no exploitation or PoC seen. Revisit once MSRC content is readable."}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}