{"id":"CVE-2026-105501","kind":"vulnerability","aliases":["CVE-2026-105501"],"related":[],"title":"Windows Installer: authorized local user can gain higher privileges","description":"Incorrect authorization in Windows Installer allows an authorized attacker to elevate privileges locally.","summary":"Windows Installer has an incorrect authorization check that lets a logged-in user with limited rights elevate their privileges on the same machine. An attacker who already has a local account can gain higher-level control of the system.","severity":"high","cvss":7.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","windows","windows-installer"],"not_affected_if":["no-local-untrusted-users"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:17:48+00:00","first_seen_at":"2026-11-10T19:24:14+00:00","triaged_at":"2026-11-10T19:42:41+00:00","updated_at":"2026-11-10T19:42:41+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-10T19:42:41Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows Installer: authorized local user can gain higher privileges","impact":"high","summary":"Windows Installer has an incorrect authorization check that lets a logged-in user with limited rights elevate their privileges on the same machine. An attacker who already has a local account can gain higher-level control of the system.","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":"Find the Microsoft security update guide entry for CVE-2026-105501 to confirm affected Windows builds and the patch.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-local-untrusted-users"],"who_is_affected":"Any Windows machine with the Windows Installer service is in scope, since the flaw is in the component itself. An attacker needs a local account on the machine first, so exposure is mainly a concern on shared or multi-user systems. The sources do not say which Windows versions are affected or what the fixed build is.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000676,"input_tokens":4482,"output_tokens":455,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the Microsoft security update guide entry for CVE-2026-105501 to confirm affected Windows builds and the patch.","search":"'-105501':12A,15A '-2026':11A,14A 'account':52B 'allow':67C 'alreadi':48B 'attack':46B,70C 'author':3A,26B,63C,69C 'check':27B 'control':58B 'cve':10A,13A 'elev':38B,72C 'gain':7A,54B 'higher':8A,56B 'higher-level':55B 'incorrect':25B,62C 'infrastructur':16B 'instal':2A,20B,22B,66C 'let':29B 'level':57B 'limit':36B 'local':4A,51B,74C 'log':32B 'logged-in':31B 'machin':44B 'privileg':9A,40B,73C 'right':37B 'system':61B 'user':5A,34B 'window':1A,17B,19B,21B,65C 'windows-instal':18B","nicknames":[],"mitigations":[],"who_affected":"Any Windows machine with the Windows Installer service is in scope, since the flaw is in the component itself. An attacker needs a local account on the machine first, so exposure is mainly a concern on shared or multi-user systems. The sources do not say which Windows versions are affected or what the fixed build is.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","infrastructure","windows","windowsinstaller"],"campaign_type":null,"search_a":"'-105501':12A,15A '-2026':11A,14A 'author':3A 'cve':10A,13A 'gain':7A 'higher':8A 'instal':2A 'local':4A 'privileg':9A 'user':5A 'window':1A","search_b":"'account':52B 'alreadi':48B 'attack':46B 'author':26B 'check':27B 'control':58B 'elev':38B 'gain':54B 'higher':56B 'higher-level':55B 'incorrect':25B 'infrastructur':16B 'instal':20B,22B 'let':29B 'level':57B 'limit':36B 'local':51B 'log':32B 'logged-in':31B 'machin':44B 'privileg':40B 'right':37B 'system':61B 'user':34B 'window':17B,19B,21B 'windows-instal':18B","search_c":"'allow':67C 'attack':70C 'author':63C,69C 'elev':72C 'incorrect':62C 'instal':66C 'local':74C 'privileg':73C 'window':65C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:17:48+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/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-2026-105501","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105501","severity":null,"published_at":"2026-11-10T19:17:48+00:00","modified_at":"2026-11-10T19:17:48+00:00","first_seen_at":"2026-11-10T19:24:14+00:00","fetched_at":"2026-11-10T19:24:14+00:00","note":null}],"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"}