Overview
What is CVE-2021-26857?
Microsoft Exchange Server Remote Code Execution Vulnerability
Source: NVD
CISA says:Apply updates per vendor instructions.CISA catalog due date May 3, 2022
CVE intelligenceCISA KEVRansomware use
CVE-2021-26857
Microsoft Exchange Server Remote Code Execution Vulnerability
7.8HIGHCVSS out of 10
What this means
Actively exploited
CISA lists CVE-2021-26857 in its Known Exploited Vulnerabilities catalog, which means exploitation has been observed. The entry applies to Microsoft Exchange Server.
- Apply updates per vendor instructions.
CISA KEVListedObserved exploitation
EPSS95.8%Estimated 30-day exploitation probability
Ransomware useReported by CISACISA KEV ransomware field
Threat actors1Source-linked actor relationships