known ransomware use

Microsoft Exchange Server Privilege Escalation Vulnerability

Added to KEV
2022-03-03
Federal due date
2022-03-17
Vendor
Microsoft
Product
Exchange Server
EPSS
99.7th percentile (score 0.918, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2018-8581

CISA short description

A privilege escalation vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could attempt to impersonate any other user of the Exchange server.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.