{"id":"CVE-2025-21335","published":"2025-01-14T18:15:58Z","modified":"2026-09-24T13:10:00Z","title":"Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability","vendor":"Microsoft","product":"Windows","tier":"core","eol":null,"description":{"text":"Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is a use-after-free vulnerability in the NT Kernel Integration Virtual Service Provider (VSP) component of Microsoft Windows Hyper-V. An attacker with low-privileged local access to the system can exploit it, without user interaction, to elevate privileges.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:42Z"},"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.01401,"percentile":0.72443,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2025-01-14","dueDate":"2025-02-04","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","notes":"https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21335 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21335","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-01-14","exploitedFirstSeen":"2025-01-14","ransomware":false,"evidence":[{"url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2025-Jan","date":"2025-01-14"},{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21335","date":"2025-01-14"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-01-14"},{"url":"https://www.kelacyber.com/resources/research/2025_midyear_threat_report/","date":"2025-08-08"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"},{"url":"https://www.ussc.ru/upload/files/%D0%9E%D1%82%D1%87%D0%B5%D1%82%20SOC.pdf","date":"2026-06-03"}],"evidenceTotal":6,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21335","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21335","tags":["US Government Resource"]}],"techniques":[{"id":"T1068","name":"Exploitation for Privilege Escalation","tactics":["privilege-escalation"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Use After Free","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability, if exploited, would allow an adversary to obtain SYSTEM-level privileges, resulting in total system compromise.","confidence":"high"},{"id":"T1003","name":"OS Credential Dumping","tactics":["credential-access"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Use After Free","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability, if exploited, would allow an adversary to obtain SYSTEM-level privileges, resulting in total system compromise.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-2400","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-2400","exploited":true,"exploitedSince":"2025-01-14","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1068"],"provenance":"source"},{"stage":"primary","techniques":["T1003"],"provenance":"source"}],"timeline":[{"date":"2025-01-14","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21335","provenance":"source"},{"date":"2025-01-14","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2025-Jan","provenance":"source"},{"date":"2025-01-14","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-01-14","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-2400","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":0},"priority":{"score":57.9,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 654 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":14.49,"detail":"percentile 0.7244"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":5.46,"detail":"base score 7.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-microsoft-windows-cwe-416"}}