Skip to content
Appaloosa Scout

KEV · Actively exploited

CVE-2021-26855

CRITICAL 9.1 KEV

Microsoft Exchange Server Remote Code Execution Vulnerability

EPSS 94.31% exploit likely percentile 100.0%

CISA Known Exploited Vulnerability

Added to KEV
2021-11-03
Remediation deadline
2022-05-03
Required action
Apply updates per vendor instructions.
Ransomware
Yes, known ransomware campaign
View on NVD ↗ CISA KEV catalog ↗