{"id":"CVE-2026-96176","kind":"vulnerability","aliases":["CVE-2026-96176"],"related":[],"title":"Windows DNS: memory not freed lets a network attacker crash the service","description":"Missing release of memory after effective lifetime in Windows DNS allows an unauthorized attacker to deny service over a network.","summary":"Windows DNS Server leaks memory after it is no longer needed, which an unauthorized attacker can trigger over the network. The result is a denial of service, meaning the DNS service can be made to stall or stop.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","self-hosted","windows","windows-dns"],"not_affected_if":["dns-server-role-not-installed","no-dns-server-role"],"how_to_check":"- Check the Windows build and patch level with `winver` or `Get-ComputerInfo` and compare against the Microsoft security update that lists CVE-2026-96176\n- Confirm the DNS Server role is installed with `Get-WindowsFeature DNS`","fix":null,"status":"open","published_at":"2026-11-10T19:22:17+00:00","first_seen_at":"2026-11-10T19:25:32+00:00","triaged_at":"2026-11-10T19:42:50+00:00","updated_at":"2026-11-10T19:44:09+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-11-10T19:42:50Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Windows DNS: memory not freed lets a network attacker crash the service","impact":"low","summary":"Windows DNS Server leaks memory after it is no longer needed, which an unauthorized attacker can trigger over the network. The result is a denial of service, meaning the DNS service can be made to stall or stop.","audience":"businesses","category":"infrastructure","nicknames":[],"who_cares":["windows","windows-dns","self-hosted"],"confidence":0.5,"fix_status":"unknown","needs_auth":"no","worst_case":"DNS service crashes or stalls, disrupting name resolution network-wide","analyst_note":"Confirm affected Windows builds and the Microsoft fix from the MSRC advisory for CVE-2026-96176; the NVD entry gives no version ranges.","how_to_check":"- Check the Windows build and patch level with `winver` or `Get-ComputerInfo` and compare against the Microsoft security update that lists CVE-2026-96176\n- Confirm the DNS Server role is installed with `Get-WindowsFeature DNS`","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["dns-server-role-not-installed"],"who_is_affected":"Windows Server machines running the DNS Server role are exposed to a network attacker. Hosts that only use DNS as a client, or that use a different DNS server, are not affected by the sources given. The sources do not state which Windows versions or configurations are vulnerable.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000725,"input_tokens":4492,"output_tokens":552,"severity_before":"high"},"analyst_status":"done","analyst_note":"Confirm affected Windows builds and the Microsoft fix from the MSRC advisory for CVE-2026-96176; the NVD entry gives no version ranges.","search":"'-2026':14A,17A '-96176':15A,18A 'allow':75C 'attack':9A,41B,78C 'crash':10A 'cve':13A,16A 'deni':80C 'denial':51B 'dns':2A,26B,28B,56B,74C 'effect':70C 'freed':5A 'host':22B 'infrastructur':19B 'leak':30B 'let':6A 'lifetim':71C 'longer':36B 'made':60B 'mean':54B 'memori':3A,31B,68C 'miss':65C 'need':37B 'network':8A,46B,84C 'releas':66C 'result':48B 'self':21B 'self-host':20B 'server':29B 'servic':12A,53B,57B,81C 'stall':62B 'stop':64B 'trigger':43B 'unauthor':40B,77C 'window':1A,23B,25B,27B,73C 'windows-dn':24B","nicknames":[],"mitigations":[],"who_affected":"Windows Server machines running the DNS Server role are exposed to a network attacker. Hosts that only use DNS as a client, or that use a different DNS server, are not affected by the sources given. The sources do not state which Windows versions or configurations are vulnerable.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","infrastructure","selfhosted","windows","windowsdns"],"campaign_type":null,"search_a":"'-2026':14A,17A '-96176':15A,18A 'attack':9A 'crash':10A 'cve':13A,16A 'dns':2A 'freed':5A 'let':6A 'memori':3A 'network':8A 'servic':12A 'window':1A","search_b":"'attack':41B 'denial':51B 'dns':26B,28B,56B 'host':22B 'infrastructur':19B 'leak':30B 'longer':36B 'made':60B 'mean':54B 'memori':31B 'need':37B 'network':46B 'result':48B 'self':21B 'self-host':20B 'server':29B 'servic':53B,57B 'stall':62B 'stop':64B 'trigger':43B 'unauthor':40B 'window':23B,25B,27B 'windows-dn':24B","search_c":"'allow':75C 'attack':78C 'deni':80C 'dns':74C 'effect':70C 'lifetim':71C 'memori':68C 'miss':65C 'network':84C 'releas':66C 'servic':81C 'unauthor':77C 'window':73C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:22:17+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-96176","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-96176","severity":null,"published_at":"2026-11-10T19:22:17+00:00","modified_at":"2026-11-10T19:22:17+00:00","first_seen_at":"2026-11-10T19:25:32+00:00","fetched_at":"2026-11-10T19:25:32+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-96176:2544","url":null,"severity":null,"published_at":"2026-11-10T19:44:09+00:00","modified_at":"2026-11-10T19:44:09+00:00","first_seen_at":"2026-11-10T19:44:09+00:00","fetched_at":"2026-11-10T19:44:09+00:00","note":"MSRC page is JS-only and returned nothing via web-cli; NVD has no versions; no search hit for this CVE. Builds, KB and fix remain unknown; nothing verified. Needs the MSRC update-guide entry (browser-cli) to settle."}],"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"}