{"id":"CVE-2026-85801","kind":"vulnerability","aliases":["CVE-2026-85801"],"related":[],"title":"Windows LSASS: use-after-free lets an authorized user gain local privileges","description":"Use after free in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to elevate privileges locally.","summary":"A use-after-free flaw in the Windows Local Security Authority Subsystem Service (LSASS) lets an attacker who already has an account on the machine raise their privileges. The sources give a CVSS score of 7.8 and say the attack is local.","severity":"high","cvss":7.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["endpoints","infrastructure","lsass","windows"],"not_affected_if":["no-local-untrusted-users"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:21:25+00:00","first_seen_at":"2026-11-10T19:25:18+00:00","triaged_at":"2026-11-10T19:38:46+00:00","updated_at":"2026-11-10T19:38:46+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T19:38:46Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows LSASS: use-after-free lets an authorized user gain local privileges","impact":"high","summary":"A use-after-free flaw in the Windows Local Security Authority Subsystem Service (LSASS) lets an attacker who already has an account on the machine raise their privileges. The sources give a CVSS score of 7.8 and say the attack is local.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","lsass","endpoints"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"local user gains SYSTEM-level privileges on the machine","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-85801 for affected Windows builds, the patch KB, and whether exploitation has been observed.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-local-untrusted-users"],"who_is_affected":"Windows machines running the LSASS service, which is present on every Windows install, so any system where an untrusted or low-privilege user can log on is in scope. The sources do not list affected Windows builds or say whether a non-default configuration is needed. Systems where only trusted administrators log on carry less risk.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000696,"input_tokens":4501,"output_tokens":491,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Check the Microsoft Security Update Guide entry for CVE-2026-85801 for affected Windows builds, the patch KB, and whether exploitation has been observed.","search":"'-2026':15A,18A '-85801':16A,19A '7.8':60B 'account':46B 'allow':78C 'alreadi':43B 'attack':41B,64B,81C 'author':9A,35B,74C,80C 'cve':14A,17A 'cvss':57B 'elev':83C 'endpoint':20B 'flaw':29B 'free':6A,28B,69C 'gain':11A 'give':55B 'infrastructur':21B 'let':7A,39B 'local':12A,33B,66B,72C,85C 'lsass':2A,22B,38B,77C 'machin':49B 'privileg':13A,52B,84C 'rais':50B 'say':62B 'score':58B 'secur':34B,73C 'servic':37B,76C 'sourc':54B 'subsystem':36B,75C 'use':4A,26B,67C 'use-after-fre':3A,25B 'user':10A 'window':1A,23B,32B,71C","nicknames":[],"mitigations":[],"who_affected":"Windows machines running the LSASS service, which is present on every Windows install, so any system where an untrusted or low-privilege user can log on is in scope. The sources do not list affected Windows builds or say whether a non-default configuration is needed. Systems where only trusted administrators log on carry less risk.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["endpoints","high","infrastructure","lsass","windows"],"campaign_type":null,"search_a":"'-2026':15A,18A '-85801':16A,19A 'author':9A 'cve':14A,17A 'free':6A 'gain':11A 'let':7A 'local':12A 'lsass':2A 'privileg':13A 'use':4A 'use-after-fre':3A 'user':10A 'window':1A","search_b":"'7.8':60B 'account':46B 'alreadi':43B 'attack':41B,64B 'author':35B 'cvss':57B 'endpoint':20B 'flaw':29B 'free':28B 'give':55B 'infrastructur':21B 'let':39B 'local':33B,66B 'lsass':22B,38B 'machin':49B 'privileg':52B 'rais':50B 'say':62B 'score':58B 'secur':34B 'servic':37B 'sourc':54B 'subsystem':36B 'use':26B 'use-after-fre':25B 'window':23B,32B","search_c":"'allow':78C 'attack':81C 'author':74C,80C 'elev':83C 'free':69C 'local':72C,85C 'lsass':77C 'privileg':84C 'secur':73C 'servic':76C 'subsystem':75C 'use':67C 'window':71C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:21:25+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-2026-85801","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85801","severity":null,"published_at":"2026-11-10T19:21:25+00:00","modified_at":"2026-11-10T19:21:25+00:00","first_seen_at":"2026-11-10T19:25:18+00:00","fetched_at":"2026-11-10T19:25:18+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"}