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CVE-2021-27065: Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server · in CISA KEV since 2021-11-03
2021-11-03added to KEV
2022-05-03federal remediation due date
99.88%EPSS exploit probability (30 days) 100.0th percentile
7.8 HIGHCVSS 3.1
Knownknown ransomware use
245days from NVD publication to KEV
What it is
Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.
Required action (CISA)
Apply updates per vendor instructions.
| CWE | CWE-39 |
|---|---|
| CVSS vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD published | 2021-03-03 (Analyzed) |
Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-27065.json · all KEV CVEs
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Get the full file: Exploited Vulnerabilities Brief – September 2026 ($29): this month's KEV additions ranked by EPSS, ransomware use and due date, ready to hand to a patch team. Checkout by Polar.