{"id":"CVE-2026-119903","kind":"vulnerability","aliases":["CVE-2026-119903"],"related":[],"title":"Windows Installer: access control flaw lets a local user gain higher privileges","description":"Improper access control in Windows Installer allows an authorized attacker to elevate privileges locally.","summary":"Windows Installer has an improper access control flaw that lets an attacker who already has a local account raise their privileges. The attacker gets elevated rights on the same machine, which can lead to full control of that 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":"- Check the Windows build with `winver` and compare it to the fixed build named in Microsoft's advisory for CVE-2026-119903 (unknown in the sources)\n- Check Windows Update history for the matching security update (unknown in the sources)","fix":null,"status":"open","published_at":"2026-11-10T19:20:10+00:00","first_seen_at":"2026-11-10T19:25:02+00:00","triaged_at":"2026-11-10T19:40:18+00:00","updated_at":"2026-11-10T19:40:18+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T19:40:18Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows Installer: access control flaw lets a local user gain higher privileges","impact":"high","summary":"Windows Installer has an improper access control flaw that lets an attacker who already has a local account raise their privileges. The attacker gets elevated rights on the same machine, which can lead to full control of that system.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","windows-installer"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"local user gains administrator rights on the machine","analyst_note":"Find the affected Windows builds and the Microsoft security update that fixes CVE-2026-119903 in the MSRC advisory; the NVD entry gave only the description.","how_to_check":"- Check the Windows build with `winver` and compare it to the fixed build named in Microsoft's advisory for CVE-2026-119903 (unknown in the sources)\n- Check Windows Update history for the matching security update (unknown in the sources)","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-local-untrusted-users"],"who_is_affected":"Any Windows machine where a user has a local account can be exposed, since the attacker must already be authorized on the system. The sources do not name the affected Windows builds. Systems where only trusted administrators log in carry lower practical risk.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000706,"input_tokens":4476,"output_tokens":517,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the affected Windows builds and the Microsoft security update that fixes CVE-2026-119903 in the MSRC advisory; the NVD entry gave only the description.","search":"'-119903':15A,18A '-2026':14A,17A 'access':3A,29B,64C 'account':41B 'allow':69C 'alreadi':37B 'attack':35B,46B,72C 'author':71C 'control':4A,30B,59B,65C 'cve':13A,16A 'elev':48B,74C 'flaw':5A,31B 'full':58B 'gain':10A 'get':47B 'higher':11A 'improp':28B,63C 'infrastructur':19B 'instal':2A,23B,25B,68C 'lead':56B 'let':6A,33B 'local':8A,40B,76C 'machin':53B 'privileg':12A,44B,75C 'rais':42B 'right':49B 'system':62B 'user':9A 'window':1A,20B,22B,24B,67C 'windows-instal':21B","nicknames":[],"mitigations":[],"who_affected":"Any Windows machine where a user has a local account can be exposed, since the attacker must already be authorized on the system. The sources do not name the affected Windows builds. Systems where only trusted administrators log in carry lower practical risk.","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":"'-119903':15A,18A '-2026':14A,17A 'access':3A 'control':4A 'cve':13A,16A 'flaw':5A 'gain':10A 'higher':11A 'instal':2A 'let':6A 'local':8A 'privileg':12A 'user':9A 'window':1A","search_b":"'access':29B 'account':41B 'alreadi':37B 'attack':35B,46B 'control':30B,59B 'elev':48B 'flaw':31B 'full':58B 'get':47B 'improp':28B 'infrastructur':19B 'instal':23B,25B 'lead':56B 'let':33B 'local':40B 'machin':53B 'privileg':44B 'rais':42B 'right':49B 'system':62B 'window':20B,22B,24B 'windows-instal':21B","search_c":"'access':64C 'allow':69C 'attack':72C 'author':71C 'control':65C 'elev':74C 'improp':63C 'instal':68C 'local':76C 'privileg':75C 'window':67C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:20:10+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-2026-119903","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119903","severity":null,"published_at":"2026-11-10T19:20:10+00:00","modified_at":"2026-11-10T19:20:10+00:00","first_seen_at":"2026-11-10T19:25:02+00:00","fetched_at":"2026-11-10T19:25:02+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"}