ACTIVELY EXPLOITED

CVE-2020-17144: Microsoft Exchange Server Remote Code Execution Vulnerability

Facts
VendorMicrosoft
ProductExchange Server
Actively exploitedYes
Added to CISA KEV3 Nov 2021
CISA federal deadline3 May 2022
Weakness (CWE)CWE-502

Required action (CISA's text)

Apply updates per vendor instructions.

Description (NVD)

Microsoft Exchange Server improperly validates cmdlet arguments which allow an attacker to perform remote code execution.

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.