{"id":"CVE-2026-112766","kind":"vulnerability","aliases":["CVE-2026-112766"],"related":[],"title":"Windows exFAT file system: use-after-free lets a local user gain privileges","description":"Use after free in Windows exFAT File System allows an authorized attacker to elevate privileges locally.","summary":"A memory-reuse bug in the Windows exFAT file system driver lets an attacker who already has a local account raise their privileges. Successful exploitation gives the attacker higher rights on the same machine.","severity":"high","cvss":7.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["exfat","infrastructure","local-users","windows"],"not_affected_if":["no-local-accounts","non-windows"],"how_to_check":"- Check the Windows build with `winver` or `systeminfo` and compare it to the fixed build named in the Microsoft advisory, which the sources do not state","fix":null,"status":"open","published_at":"2026-11-10T19:18:40+00:00","first_seen_at":"2026-11-10T19:24:32+00:00","triaged_at":"2026-11-10T19:53:43+00:00","updated_at":"2026-11-10T19:53:43+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-11-10T19:53:43Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows exFAT file system: use-after-free lets a local user gain privileges","impact":"high","summary":"A memory-reuse bug in the Windows exFAT file system driver lets an attacker who already has a local account raise their privileges. Successful exploitation gives the attacker higher rights on the same machine.","audience":"everyone","category":"infrastructure","nicknames":[],"who_cares":["windows","exfat","local-users"],"confidence":0.6,"fix_status":"unknown","needs_auth":"yes","worst_case":"local attacker gains elevated privileges on the Windows machine","analyst_note":"Confirm the affected Windows builds and the Microsoft fixed build from the MSRC advisory for CVE-2026-112766.","how_to_check":"- Check the Windows build with `winver` or `systeminfo` and compare it to the fixed build named in the Microsoft advisory, which the sources do not state\n- unknown","plain_action":"Install the latest Windows security update from Windows Update.","product_name":"","needs_analyst":true,"not_affected_if":["no-local-accounts","non-windows"],"who_is_affected":"Any Windows machine where a person or process can log on locally and the exFAT driver is present. Shared computers and multi-user servers carry the most risk. The sources do not say whether non-exFAT-mounted systems are exposed.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000702,"input_tokens":4480,"output_tokens":508,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Confirm the affected Windows builds and the Microsoft fixed build from the MSRC advisory for CVE-2026-112766.","search":"'-112766':17A,20A '-2026':16A,19A 'account':47B 'allow':70C 'alreadi':43B 'attack':41B,55B,73C 'author':72C 'bug':31B 'cve':15A,18A 'driver':38B 'elev':75C 'exfat':2A,21B,35B,67C 'exploit':52B 'file':3A,36B,68C 'free':8A,64C 'gain':13A 'give':53B 'higher':56B 'infrastructur':22B 'let':9A,39B 'local':11A,24B,46B,77C 'local-us':23B 'machin':61B 'memori':29B 'memory-reus':28B 'privileg':14A,50B,76C 'rais':48B 'reus':30B 'right':57B 'success':51B 'system':4A,37B,69C 'use':6A,62C 'use-after-fre':5A 'user':12A,25B 'window':1A,26B,34B,66C","nicknames":[],"mitigations":[],"who_affected":"Any Windows machine where a person or process can log on locally and the exFAT driver is present. Shared computers and multi-user servers carry the most risk. The sources do not say whether non-exFAT-mounted systems are exposed.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"everyone","plain_action":null,"pkeys":[],"ptokens":[],"labels":["exfat","high","infrastructure","localusers","windows"],"campaign_type":null,"search_a":"'-112766':17A,20A '-2026':16A,19A 'cve':15A,18A 'exfat':2A 'file':3A 'free':8A 'gain':13A 'let':9A 'local':11A 'privileg':14A 'system':4A 'use':6A 'use-after-fre':5A 'user':12A 'window':1A","search_b":"'account':47B 'alreadi':43B 'attack':41B,55B 'bug':31B 'driver':38B 'exfat':21B,35B 'exploit':52B 'file':36B 'give':53B 'higher':56B 'infrastructur':22B 'let':39B 'local':24B,46B 'local-us':23B 'machin':61B 'memori':29B 'memory-reus':28B 'privileg':50B 'rais':48B 'reus':30B 'right':57B 'success':51B 'system':37B 'user':25B 'window':26B,34B","search_c":"'allow':70C 'attack':73C 'author':72C 'elev':75C 'exfat':67C 'file':68C 'free':64C 'local':77C 'privileg':76C 'system':69C 'use':62C 'window':66C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:18:40+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:H/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-2026-112766","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112766","severity":null,"published_at":"2026-11-10T19:18:40+00:00","modified_at":"2026-11-10T19:18:40+00:00","first_seen_at":"2026-11-10T19:24:32+00:00","fetched_at":"2026-11-10T19:24:32+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"}