Date
Immediate patching or mitigation to avoid exploitation recommended!
The vulnerabilities exploited by HAFNIUM were CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065. Exchange mail server products from 2013 and later (2016, 2019) were found to be vulnerable
read more at: https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers