CVE-2020-16875
Published: April 11, 2026
Official Description
A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.
An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. Exploitation of the vulnerability requires an authenticated user in a certain Exchange role to be compromised.
The security update addresses the vulnerability by correcting how Microsoft Exchange handles cmdlet arguments.
Risk Analysis
Microsoft Exchange Server has a remote code execution vulnerability due to improper validation of cmdlet arguments. An attacker who compromises an authenticated user in a specific Exchange role could execute arbitrary code with System privileges.
This vulnerability has been actively exploited in the wild and is listed in CISA's KEV catalog. Exploitation requires an authenticated user, but the impact is severe.
Apply the security update from Microsoft that corrects how Exchange handles cmdlet arguments. Implement strong authentication and least privilege principles for Exchange users and administrators.
Technical Analysis
CVE-2020-16875 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2020-16875 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-16875 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1