Microsoft Exchange Server 2016 Cumulative Update 20

14 known vulnerabilities.

Microsoft Exchange Server 2016 Cumulative Update 20 at a glance

Last 12 months: 0
Critical · all time: 5
Exploited · all time: 5
Public exploit · all time: 6

3 of the exploited vulnerabilities are known to be used by ransomware (CISA).

New vulnerabilities per month · last 2412 months

Show as table

Month	Vulnerabilities	Critical
Nov 2026	0	0
Oct 2026	0	0
Sep 2026	0	0
Aug 2026	0	0
Jul 2026	0	0
Jun 2026	0	0
May 2026	0	0
Apr 2026	0	0
Mar 2026	0	0
Feb 2026	0	0
Jan 2026	0	0
Dec 2025	0	0
Nov 2025	0	0
Oct 2025	0	0
Sep 2025	0	0
Aug 2025	0	0
Jul 2025	0	0
Jun 2025	0	0
May 2025	0	0
Apr 2025	0	0
Mar 2025	0	0
Feb 2025	0	0
Jan 2025	0	0
Dec 2024	0	0

Most common weaknesses

All Critical High Medium Low Exploited only Public exploit

14 results · Feed

Critical 9.0

CVE-2021-34523 Exploited · Ransomware Public exploit EPSS 100%

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 19 Microsoft Exchange Server 2019 Cumulative Update 8

Jul 14, 2021
KEV Nov 3, 2021
Critical 9.1

CVE-2021-34473 Exploited · Ransomware Public exploit Scanner template EPSS 100%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

Jul 14, 2021
KEV Nov 3, 2021
High 8.0

CVE-2021-33768

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Microsoft Exchange Server 2019 Cumulative Update 10 Microsoft Exchange Server 2016 Cumulative Update 21 Microsoft Exchange Server 2016 Cumulative Update 20

Jul 14, 2021
High 7.3

CVE-2021-33766 Exploited Public exploit Scanner template EPSS 98%

Microsoft Exchange Server Information Disclosure Vulnerability

Microsoft Exchange Server Information Disclosure Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

Jul 14, 2021
KEV Jan 18, 2022
High 7.6

CVE-2021-31206 EPSS 13%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 21 Microsoft Exchange Server 2019 Cumulative Update 10

Jul 14, 2021
High 7.2

CVE-2021-31196 Exploited EPSS 54%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 21 Microsoft Exchange Server 2019 Cumulative Update 10

Jul 14, 2021
KEV Aug 21, 2024
Medium 6.5

CVE-2021-31209

Microsoft Exchange Server Spoofing Vulnerability

Microsoft Exchange Server Spoofing Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 19 Microsoft Exchange Server 2019 Cumulative Update 8

May 11, 2021
Medium 6.6

CVE-2021-31207 Exploited · Ransomware Public exploit EPSS 100%

Microsoft Exchange Server Security Feature Bypass Vulnerability

Microsoft Exchange Server Security Feature Bypass Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 19 Microsoft Exchange Server 2019 Cumulative Update 8

May 11, 2021
KEV Nov 3, 2021
High 7.8

CVE-2021-31198

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

May 11, 2021
Medium 6.5

CVE-2021-31195 Scanner template EPSS 74%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

May 11, 2021
Critical 9.0

CVE-2021-28483

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

Apr 13, 2021
High 8.8

CVE-2021-28482 Public exploit EPSS 83%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2016 Cumulative Update 19 Microsoft Exchange Server 2019 Cumulative Update 8

Apr 13, 2021
Critical 9.8

CVE-2021-28481 Scanner template EPSS 36%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

Apr 13, 2021
Critical 9.8

CVE-2021-28480 Public exploit Scanner template EPSS 71%

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 Microsoft Exchange Server 2019 Cumulative Update 8 Microsoft Exchange Server 2016 Cumulative Update 19

Apr 13, 2021

Microsoft Exchange Server 2016 Cumulative Update 20

Microsoft Exchange Server 2016 Cumulative Update 20 at a glance

Most common weaknesses

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Elevation of Privilege Vulnerability

Microsoft Exchange Server Information Disclosure Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Spoofing Vulnerability

Microsoft Exchange Server Security Feature Bypass Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability