{"id":"CVE-2026-105527","kind":"vulnerability","aliases":["CVE-2026-105527"],"related":[],"title":"Windows EFS: untrusted pointer dereference lets an authorized user crash the system","description":"Untrusted pointer dereference in Windows Encrypting File System (EFS) allows an authorized attacker to deny service locally.","summary":"Windows Encrypting File System (EFS) dereferences an untrusted pointer, a memory handling flaw. An authorized local user can trigger it to deny service on the machine.","severity":"medium","cvss":5.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["efs","infrastructure","windows"],"not_affected_if":["no-local-untrusted-users"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:17:52+00:00","first_seen_at":"2026-11-10T19:24:18+00:00","triaged_at":"2026-11-10T20:02:21+00:00","updated_at":"2026-11-10T20:02:21+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-11-10T20:02:21Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Windows EFS: untrusted pointer dereference lets an authorized user crash the system","impact":"low","summary":"Windows Encrypting File System (EFS) dereferences an untrusted pointer, a memory handling flaw. An authorized local user can trigger it to deny service on the machine.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","efs"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"local denial of service, machine crashes or hangs","analyst_note":"","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["no-local-untrusted-users"],"who_is_affected":"Affects Windows machines where EFS is in use; the sources do not name affected builds. Only a local user with some authorized access can trigger it, so systems with no such local users are at lower risk. unknown","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000636,"input_tokens":4500,"output_tokens":372,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-105527':15A,18A '-2026':14A,17A 'allow':57C 'attack':60C 'author':8A,36B,59C 'crash':10A 'cve':13A,16A 'deni':43B,62C 'derefer':5A,27B,50C 'ef':2A,19B,26B,56C 'encrypt':23B,53C 'file':24B,54C 'flaw':34B 'handl':33B 'infrastructur':20B 'let':6A 'local':37B,64C 'machin':47B 'memori':32B 'pointer':4A,30B,49C 'servic':44B,63C 'system':12A,25B,55C 'trigger':40B 'untrust':3A,29B,48C 'user':9A,38B 'window':1A,21B,22B,52C","nicknames":[],"mitigations":[],"who_affected":"Affects Windows machines where EFS is in use; the sources do not name affected builds. Only a local user with some authorized access can trigger it, so systems with no such local users are at lower risk. unknown","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["efs","infrastructure","medium","windows"],"campaign_type":null,"search_a":"'-105527':15A,18A '-2026':14A,17A 'author':8A 'crash':10A 'cve':13A,16A 'derefer':5A 'ef':2A 'let':6A 'pointer':4A 'system':12A 'untrust':3A 'user':9A 'window':1A","search_b":"'author':36B 'deni':43B 'derefer':27B 'ef':19B,26B 'encrypt':23B 'file':24B 'flaw':34B 'handl':33B 'infrastructur':20B 'local':37B 'machin':47B 'memori':32B 'pointer':30B 'servic':44B 'system':25B 'trigger':40B 'untrust':29B 'user':38B 'window':21B,22B","search_c":"'allow':57C 'attack':60C 'author':59C 'deni':62C 'derefer':50C 'ef':56C 'encrypt':53C 'file':54C 'local':64C 'pointer':49C 'servic':63C 'system':55C 'untrust':48C 'window':52C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:17:52+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-105527","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105527","severity":null,"published_at":"2026-11-10T19:17:52+00:00","modified_at":"2026-11-10T19:17:52+00:00","first_seen_at":"2026-11-10T19:24:18+00:00","fetched_at":"2026-11-10T19:24:18+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"}