Actively exploited in the wild
Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft - Exchange Server · Listed in the CISA KEV since 2021-11-03. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2021-26855
CriticalCVSS 9.1KEVExploitation Probability (EPSS)
Very high risk100th percentile - higher than 100% of all known CVEs
Summary
Microsoft Exchange Server contains a remote code execution vulnerability. This vulnerability can be exploited by an attacker to execute arbitrary code on the server.
Risk Assessment
An attacker can take control of the Exchange server, potentially leading to data theft, email compromise, and further propagation of attacks within the network.
Recommendation
Immediately apply security updates released by Microsoft for Exchange Server.
Original NVD description (English source)
Microsoft Exchange Server Remote Code Execution Vulnerability