known ransomware use

Microsoft Exchange Server Remote Code Execution Vulnerability

Added to KEV
2022-09-30
Federal due date
2022-10-21
Vendor
Microsoft
Product
Exchange Server
EPSS
99.6th percentile (score 0.908, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Known
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2022-41082

CISA short description

Microsoft Exchange Server contains an unspecified vulnerability that allows for authenticated remote code execution. Dubbed "ProxyNotShell," this vulnerability is chainable with CVE-2022-41040 which allows for the remote code execution.

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.