Exchange Server vulnerabilitiesAnd the versions its exploited flaws hit.
Exchange Server is made by Microsoft. We track 232 published vulnerabilities in it, across 10 versions. 19 of them are on the list of flaws known to be exploited, the newest added on 13 April 2026. If you run Exchange Server, check your version against the exploited flaws below and patch those first.
The most recent Exchange Server flaw added to the known-exploited list is CVE-2023-21529, on 13 April 2026. We keep watching the known-exploited list.
Which versions of Exchange Server do the exploited flaws hit?
Each exploited flaw lists the versions it affects, as published by the vendor. Find your version, then patch.
- CVE-2023-21529Exploited list, 13 Apr 2026
Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability
2013-cumulative_update_232016-cumulative_update_232019-cumulative_update_112019-cumulative_update_12 - CVE-2021-31196Exploited list, 21 Aug 2024
Microsoft Exchange Server Information Disclosure Vulnerability
2013-cumulative_update_232016-cumulative_update_202016-cumulative_update_212019-cumulative_update_92019-cumulative_update_10 - CVE-2024-21410Exploited list, 15 Feb 2024
Microsoft Exchange Server Privilege Escalation Vulnerability
2016-cumulative_update_232019-cumulative_update_132019-cumulative_update_14 - CVE-2022-41080Exploited list, 10 Jan 2023
Microsoft Exchange Server Privilege Escalation Vulnerability
2013-cumulative_update_232016-cumulative_update_222016-cumulative_update_232019-cumulative_update_112019-cumulative_update_12 - CVE-2022-41040Exploited list, 30 Sep 2022
Microsoft Exchange Server Server-Side Request Forgery Vulnerability
2013-cumulative_update_232016-cumulative_update_222016-cumulative_update_232019-cumulative_update_112019-cumulative_update_12 - CVE-2022-41082Exploited list, 30 Sep 2022
Microsoft Exchange Server Remote Code Execution Vulnerability
2013-cumulative_update_232016-cumulative_update_222016-cumulative_update_232019-cumulative_update_112019-cumulative_update_12 - CVE-2017-8540Exploited list, 3 Mar 2022
Microsoft Malware Protection Engine Improper Restriction of Operations Vulnerability
20132016 - CVE-2018-8581Exploited list, 3 Mar 2022
Microsoft Exchange Server Privilege Escalation Vulnerability
2010201320162019 - CVE-2021-33766Exploited list, 18 Jan 2022
Microsoft Exchange Server Information Disclosure
2013-cumulative_update_232016-cumulative_update_192016-cumulative_update_202019-cumulative_update_82019-cumulative_update_9 - CVE-2021-42321Exploited list, 17 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2016-cumulative_update_212016-cumulative_update_222019-cumulative_update_102019-cumulative_update_11 - CVE-2021-34473Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2013-cumulative_update_232016-cumulative_update_192016-cumulative_update_202019-cumulative_update_82019-cumulative_update_9 - CVE-2021-34523Exploited list, 3 Nov 2021
Microsoft Exchange Server Privilege Escalation Vulnerability
2013-cumulative_update_232016-cumulative_update_192016-cumulative_update_202019-cumulative_update_82019-cumulative_update_9 - CVE-2021-26858Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2010-sp32013-cumulative_update_222013-cumulative_update_232013-sp12016-cumulative_update_82016-cumulative_update_92016-cumulative_update_102016-cumulative_update_11 - CVE-2021-26857Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2010-sp32013-cumulative_update_222013-cumulative_update_232013-sp12016-cumulative_update_82016-cumulative_update_92016-cumulative_update_102016-cumulative_update_11 - CVE-2021-26855Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2013-cumulative_update_212013-cumulative_update_222013-cumulative_update_232016-cumulative_update_82016-cumulative_update_92016-cumulative_update_102016-cumulative_update_112016-cumulative_update_12 - CVE-2020-17144Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2010-sp3_rollup_31 - CVE-2021-27065Exploited list, 3 Nov 2021
Microsoft Exchange Server Remote Code Execution Vulnerability
2013-cumulative_update_212013-sp12016-cumulative_update_82016-cumulative_update_102016-cumulative_update_112016-cumulative_update_122016-cumulative_update_132016-cumulative_update_14 - CVE-2020-0688Exploited list, 3 Nov 2021
Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability
2010-sp3_rollup_302013-cumulative_update_232016-cumulative_update_142016-cumulative_update_152019-cumulative_update_32019-cumulative_update_4 - CVE-2021-31207Exploited list, 3 Nov 2021
Microsoft Exchange Server Security Feature Bypass Vulnerability
2013-cumulative_update_232016-cumulative_update_192016-cumulative_update_202019-cumulative_update_82019-cumulative_update_9
Which Exchange Server vulnerabilities are being exploited?
19 flaws are on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.
- 8.8Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability
Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.
- 7.2Microsoft Exchange Server Information Disclosure Vulnerability
Microsoft Exchange Server contains an information disclosure vulnerability that allows for remote code execution.
- 9.8Microsoft Exchange Server Privilege Escalation Vulnerability
Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.
- 8.8Microsoft Exchange Server Privilege Escalation Vulnerability
Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.
- 8.8Microsoft Exchange Server Server-Side Request Forgery Vulnerability
Microsoft Exchange Server allows for server-side request forgery.
- 8.0Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server contains an unspecified vulnerability that allows for authenticated remote code execution.
- 7.8Microsoft Malware Protection Engine Improper Restriction of Operations Vulnerability
The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Microsoft Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT...
- 7.4Microsoft Exchange Server Privilege Escalation Vulnerability
A privilege escalation vulnerability exists in Microsoft Exchange Server.
Which Exchange Server flaws are most likely to be used?
Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.
- >99%
Microsoft Exchange Server Remote Code Execution Vulnerability
- >99%
Microsoft Exchange Server Remote Code Execution Vulnerability
- >99%
Microsoft Exchange Server Elevation of Privilege Vulnerability
- >99%
Microsoft Exchange Server Remote Code Execution Vulnerability
- >99%
A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
- >99%
Microsoft Exchange Server Elevation of Privilege Vulnerability
- >99%
Microsoft Exchange Server Remote Code Execution Vulnerability
- >99%
Microsoft Exchange Server Security Feature Bypass Vulnerability
- 98%
Microsoft Exchange Server Information Disclosure Vulnerability
- 96%
Microsoft Exchange Server Remote Code Execution Vulnerability
Running Exchange Server? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
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1 flaw being exploited affects software Acme tracks
Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.
- Matched to
- Exchange Server on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
We track 232 published vulnerabilities listed under the name Exchange Server, across 10 versions. The most recent Exchange Server flaw added to the known-exploited list is CVE-2023-21529, on 13 April 2026.
19 are on the list of flaws known to be exploited. The most recently added are CVE-2023-21529, CVE-2021-31196 and CVE-2024-21410.
Each flaw names its own versions, usually as ranges. The newest, CVE-2023-21529, affects 2013-cumulative_update_23, 2016-cumulative_update_23, 2019-cumulative_update_11, 2019-cumulative_update_12. The versions for every exploited flaw are listed on this page.
Create a EdgeProtect account and track Exchange Server. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.