{"id":"CVE-2025-64666","published":"2025-12-09T17:55:45Z","modified":"2026-04-16T14:18:39Z","title":"Microsoft Exchange Server Elevation of Privilege Vulnerability","vendor":"Microsoft","product":"Microsoft Exchange Server 2016 Cumulative Update 23","tier":"tail","description":{"text":"Improper input validation in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.","provenance":"source","from":"CVE.org"},"cvss":{"score":7.5,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.0102,"percentile":0.63283,"provenance":"source"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-64666","tags":["vendor-advisory","patch"]}],"priority":{"score":17.9,"factors":[{"name":"EPSS percentile","points":12.66},{"name":"CVSS severity","points":5.25}]},"vendorSlug":"microsoft","affectedVersions":[{"vendor":"Microsoft","product":"Microsoft Exchange Server 2016 Cumulative Update 23","versions":[">= 15.01.0.0, < 15.01.2507.063"]},{"vendor":"Microsoft","product":"Microsoft Exchange Server 2019 Cumulative Update 14","versions":[">= 15.02.0.0, < 15.02.1544.037"]},{"vendor":"Microsoft","product":"Microsoft Exchange Server 2019 Cumulative Update 15","versions":[">= 15.02.0.0, < 15.02.1748.042"]},{"vendor":"Microsoft","product":"Microsoft Exchange Server Subscription Edition RTM","versions":[">= 15.02.0.0, < 15.02.2562.035"]}],"euvd":{"id":"EUVD-2025-202236","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-class-microsoft-exchange-server-cwe-20"}}