{"id":"CVE-2026-119826","kind":"vulnerability","aliases":["CVE-2026-119826"],"related":[],"title":"Windows Hyper-V: use-after-free lets a local user gain higher privileges","description":"Use after free in Windows Hyper-V allows an authorized attacker to elevate privileges locally.","summary":"A memory-handling bug in Windows Hyper-V lets a user who already has access to the machine escalate their privileges. The sources do not say which Windows builds are affected or what patch fixes it.","severity":"high","cvss":7.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["hyper-v","infrastructure","windows"],"not_affected_if":["hyper-v-not-enabled","no-untrusted-local-users"],"how_to_check":"- Check the installed Windows build with `winver` and compare it against Microsoft's security update guide entry for CVE-2026-119826\n- Check whether the Hyper-V role is enabled, for example with `Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V`","fix":null,"status":"open","published_at":"2026-11-10T19:19:57+00:00","first_seen_at":"2026-11-10T19:24:57+00:00","triaged_at":"2026-11-10T19:40:26+00:00","updated_at":"2026-11-10T19:40:26+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T19:40:26Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows Hyper-V: use-after-free lets a local user gain higher privileges","impact":"high","summary":"A memory-handling bug in Windows Hyper-V lets a user who already has access to the machine escalate their privileges. The sources do not say which Windows builds are affected or what patch fixes it.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","hyper-v"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"local user gains elevated system privileges on the Windows host","analyst_note":"Find the affected Windows builds and the Microsoft patch from the Security Update Guide entry for CVE-2026-119826; NVD alone gives neither.","how_to_check":"- Check the installed Windows build with `winver` and compare it against Microsoft's security update guide entry for CVE-2026-119826\n- Check whether the Hyper-V role is enabled, for example with `Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V`","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["hyper-v-not-enabled","no-untrusted-local-users"],"who_is_affected":"Only Windows machines with the Hyper-V feature present are relevant, and the attacker needs an authorized local account first. The sources do not list affected builds, so the exact exposure is unknown. Systems without Hyper-V or with no untrusted local users are lower priority.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000731,"input_tokens":4480,"output_tokens":565,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find the affected Windows builds and the Microsoft patch from the Security Update Guide entry for CVE-2026-119826; NVD alone gives neither.","search":"'-119826':18A,21A '-2026':17A,20A 'access':43B 'affect':59B 'allow':72C 'alreadi':41B 'attack':75C 'author':74C 'bug':31B 'build':57B 'cve':16A,19A 'elev':77C 'escal':47B 'fix':63B 'free':8A,66C 'gain':13A 'handl':30B 'higher':14A 'hyper':3A,23B,35B,70C 'hyper-v':2A,22B,34B,69C 'infrastructur':25B 'let':9A,37B 'local':11A,79C 'machin':46B 'memori':29B 'memory-handl':28B 'patch':62B 'privileg':15A,49B,78C 'say':54B 'sourc':51B 'use':6A,64C 'use-after-fre':5A 'user':12A,39B 'v':4A,24B,36B,71C 'window':1A,26B,33B,56B,68C","nicknames":[],"mitigations":[],"who_affected":"Only Windows machines with the Hyper-V feature present are relevant, and the attacker needs an authorized local account first. The sources do not list affected builds, so the exact exposure is unknown. Systems without Hyper-V or with no untrusted local users are lower priority.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","hyperv","infrastructure","windows"],"campaign_type":null,"search_a":"'-119826':18A,21A '-2026':17A,20A 'cve':16A,19A 'free':8A 'gain':13A 'higher':14A 'hyper':3A 'hyper-v':2A 'let':9A 'local':11A 'privileg':15A 'use':6A 'use-after-fre':5A 'user':12A 'v':4A 'window':1A","search_b":"'access':43B 'affect':59B 'alreadi':41B 'bug':31B 'build':57B 'escal':47B 'fix':63B 'handl':30B 'hyper':23B,35B 'hyper-v':22B,34B 'infrastructur':25B 'let':37B 'machin':46B 'memori':29B 'memory-handl':28B 'patch':62B 'privileg':49B 'say':54B 'sourc':51B 'user':39B 'v':24B,36B 'window':26B,33B,56B","search_c":"'allow':72C 'attack':75C 'author':74C 'elev':77C 'free':66C 'hyper':70C 'hyper-v':69C 'local':79C 'privileg':78C 'use':64C 'v':71C 'window':68C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:57+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-2026-119826","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119826","severity":null,"published_at":"2026-11-10T19:19:57+00:00","modified_at":"2026-11-10T19:19:57+00:00","first_seen_at":"2026-11-10T19:24:57+00:00","fetched_at":"2026-11-10T19:24:57+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"}