{"id":"CVE-2026-113861","kind":"vulnerability","aliases":["CVE-2026-113861"],"related":[],"title":"Windows Hyper-V: use-after-free lets an authorized user gain higher privileges","description":"Use after free in Windows Hyper-V allows an authorized attacker to elevate privileges locally.","summary":"A use-after-free bug in Windows Hyper-V lets a user who already has an account on the machine elevate their privileges. An attacker who gets this far can take over the local system.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Windows Hyper-V","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["hyper-v","infrastructure","privilege-escalation","windows"],"not_affected_if":["hyper-v-disabled"],"how_to_check":"Check whether the Hyper-V role/feature is enabled (PowerShell: Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V). If so, confirm the November 2026 cumulative update (released 2026-11-10) is installed. The exact fixed build is unknown until the MSRC entry is read.","fix":"Install the November 2026 Windows cumulative update (Patch Tuesday, 2026-11-10) on Hyper-V hosts. Exact fixed builds/KBs unknown: see the MSRC Security Update Guide entry for CVE-2026-113861.","status":"open","published_at":"2026-11-10T19:19:06+00:00","first_seen_at":"2026-11-10T19:24:42+00:00","triaged_at":"2026-11-10T19:45:02+00:00","updated_at":"2026-11-10T23:48:09+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-11-10T19:45:02Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows Hyper-V: use-after-free lets an authorized user gain higher privileges","impact":"high","summary":"A use-after-free bug in Windows Hyper-V lets a user who already has an account on the machine elevate their privileges. An attacker who gets this far can take over the local system.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","hyper-v"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"local user gains system-level privileges on the machine","analyst_note":"Find the Microsoft security update guide entry for this CVE to confirm affected Windows builds, fixed builds and any Hyper-V-specific check.","how_to_check":"- unknown","plain_action":"","product_name":"Windows Hyper-V","needs_analyst":true,"not_affected_if":["hyper-v-disabled"],"who_is_affected":"Machines running Windows with the Hyper-V feature enabled are the systems to look at. The sources do not say which Windows builds are affected, so unknown. Systems without Hyper-V can likely skip it, but the sources do not confirm that.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000679,"input_tokens":4480,"output_tokens":463,"severity_before":"high"},"analyst_status":"done","analyst_note":"Find the Microsoft security update guide entry for this CVE to confirm affected Windows builds, fixed builds and any Hyper-V-specific check.","search":"'-113861':18A,21A '-2026':17A,20A 'account':52B 'allow':79C 'alreadi':49B 'attack':60B,82C 'author':11A,81C 'bug':39B 'cve':16A,19A 'elev':56B,84C 'escal':32B 'far':64B 'free':8A,38B,73C 'gain':13A 'get':62B 'higher':14A 'hyper':3A,24A,27B,43B,77C 'hyper-v':2A,23A,26B,42B,76C 'infrastructur':29B 'let':9A,45B 'local':69B,86C 'machin':55B 'privileg':15A,31B,58B,85C 'privilege-escal':30B 'system':70B 'take':66B 'use':6A,36B,71C 'use-after-fre':5A,35B 'user':12A,47B 'v':4A,25A,28B,44B,78C 'window':1A,33B,41B,75C 'windows':22A","nicknames":[],"mitigations":[],"who_affected":"Windows machines with the Hyper-V role or feature enabled, especially shared Hyper-V hosts where a local privilege escalation could affect every workload. Per the NVD CVSS vector the attacker needs high privileges locally and the attack is complex. Machines without Hyper-V can likely skip it, but affected builds are not confirmed from Microsoft's page.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":["hyperv","windowshyperv"],"ptokens":["hyper","windows"],"labels":["high","hyperv","infrastructure","privilegeescalation","vendor","windows"],"campaign_type":null,"search_a":"'-113861':18A,21A '-2026':17A,20A 'author':11A 'cve':16A,19A 'free':8A 'gain':13A 'higher':14A 'hyper':3A,24A 'hyper-v':2A,23A 'let':9A 'privileg':15A 'use':6A 'use-after-fre':5A 'user':12A 'v':4A,25A 'window':1A 'windows':22A","search_b":"'account':52B 'alreadi':49B 'attack':60B 'bug':39B 'elev':56B 'escal':32B 'far':64B 'free':38B 'get':62B 'hyper':27B,43B 'hyper-v':26B,42B 'infrastructur':29B 'let':45B 'local':69B 'machin':55B 'privileg':31B,58B 'privilege-escal':30B 'system':70B 'take':66B 'use':36B 'use-after-fre':35B 'user':47B 'v':28B,44B 'window':33B,41B","search_c":"'allow':79C 'attack':82C 'author':81C 'elev':84C 'free':73C 'hyper':77C 'hyper-v':76C 'local':86C 'privileg':85C 'use':71C 'v':78C 'window':75C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:06+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-113861","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-113861","severity":null,"published_at":"2026-11-10T19:19:06+00:00","modified_at":"2026-11-10T19:19:06+00:00","first_seen_at":"2026-11-10T19:24:42+00:00","fetched_at":"2026-11-10T19:24:42+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-113861:3233","url":"https://beyondmachines.net/event_details/microsoft-patches-1235-flaws-in-november-2026-update-including-actively-exploited-outlook-flaw-a-y-v-q-f","severity":null,"published_at":"2026-11-10T23:48:09+00:00","modified_at":"2026-11-10T23:48:09+00:00","first_seen_at":"2026-11-10T23:48:09+00:00","fetched_at":"2026-11-10T23:48:09+00:00","note":"Fixed in Microsoft's Nov 2026 Patch Tuesday per a secondary report (beyondmachines). MSRC guide page is JS-only and unreadable here (web-cli empty, browser quota exhausted), so builds and KBs are unconfirmed. Nothing verified. Revisit with MSRC data.","cites":["https://beyondmachines.net/event_details/microsoft-patches-1235-flaws-in-november-2026-update-including-actively-exploited-outlook-flaw-a-y-v-q-f"]}],"documents":[{"id":120454,"url":"https://beyondmachines.net/event_details/microsoft-patches-1235-flaws-in-november-2026-update-including-actively-exploited-outlook-flaw-a-y-v-q-f","title":"Microsoft Patches 1,235 Flaws in November 2026 Update (BeyondMachines)","kind":"blog","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"mentions","confidence":null,"note":null}],"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"}