Microsoft · Vulnerability intelligence
Microsoft Exchange Server
Our sources currently list 247 known vulnerabilities affecting Microsoft Exchange Server. 26 are rated critical severity. 20 of 247 are actively exploited according to CISA, the most recent added 15 May 2026.
Last updated: 22 July 2026, 20:30 AEST
Australian advisories
| CVE | Severity | Exploitation | Published | Summary |
|---|---|---|---|---|
| CVE-2021-26855 | Critical (9.1) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-34473 | Critical (9.1) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-34523 | Critical (9.0) | Actively exploited · ransomware | Microsoft Exchange Server Elevation of Privilege Vulnerability | |
| CVE-2022-41082 | High (8.0) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2020-0688 | High (8.8) | Actively exploited · ransomware | 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 … | |
| CVE-2021-27065 | High (7.8) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2022-41040 | High (8.8) | Actively exploited · ransomware | Microsoft Exchange Server Elevation of Privilege Vulnerability | |
| CVE-2021-31207 | Medium (6.6) | Actively exploited · ransomware | Microsoft Exchange Server Security Feature Bypass Vulnerability | |
| CVE-2021-33766 | High (7.3) | Actively exploited | Microsoft Exchange Server Information Disclosure Vulnerability | |
| CVE-2021-26857 | High (7.8) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-42321 | High (8.8) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-26858 | High (7.8) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2022-41080 | High (8.8) | Actively exploited · ransomware | Microsoft Exchange Server Elevation of Privilege Vulnerability | |
| CVE-2017-8540 | High (7.8) | Actively exploited | 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 S… | |
| CVE-2023-21529 | High (8.8) | Actively exploited · ransomware | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-31196 | High (7.2) | Actively exploited | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2020-17144 | High (8.4) | Actively exploited | Microsoft Exchange Remote Code Execution Vulnerability | |
| CVE-2018-8581 | High (7.4) | Actively exploited · ransomware | An elevation of privilege vulnerability exists in Microsoft Exchange Server, aka "Microsoft Exchange Server Elevation of Privilege Vulnerability." This affects Microsoft Exchange S… | |
| CVE-2024-21410 | Critical (9.8) | Actively exploited | Microsoft Exchange Server Elevation of Privilege Vulnerability | |
| CVE-2026-42897 | High (8.1) | Actively exploited | Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network… | |
| CVE-2021-41349 | Medium (6.5) | Elevated likelihood (94%) | Microsoft Exchange Server Spoofing Vulnerability | |
| CVE-2020-17132 | Critical (9.1) | Elevated likelihood (90%) | Microsoft Exchange Remote Code Execution Vulnerability | |
| CVE-2023-36035 | High (8.0) | Elevated likelihood (87%) | Microsoft Exchange Server Spoofing Vulnerability | |
| CVE-2021-28482 | High (8.8) | Elevated likelihood (83%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2023-21707 | High (8.8) | Elevated likelihood (82%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2023-32031 | High (8.8) | Elevated likelihood (82%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2023-36744 | High (8.0) | Elevated likelihood (82%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2023-36777 | Medium (5.7) | Elevated likelihood (81%) | Microsoft Exchange Server Information Disclosure Vulnerability | |
| CVE-2023-36745 | High (8.0) | Elevated likelihood (81%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2006-0027 | High (7.5) | Elevated likelihood (79%) | Unspecified vulnerability in Microsoft Exchange allows remote attackers to execute arbitrary code via e-mail messages with crafted (1) vCal or (2) iCal Calendar properties. | |
| CVE-2003-0714 | High (7.5) | Elevated likelihood (76%) | The Internet Mail Service in Exchange Server 5.5 and Exchange 2000 allows remote attackers to cause a denial of service (memory exhaustion) by directly connecting to the SMTP servi… | |
| CVE-2023-36756 | High (8.0) | Elevated likelihood (75%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2021-31195 | Medium (6.5) | Elevated likelihood (74%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2023-36039 | High (8.0) | Elevated likelihood (73%) | Microsoft Exchange Server Spoofing Vulnerability | |
| CVE-2021-28480 | Critical (9.8) | Elevated likelihood (71%) | Microsoft Exchange Server Remote Code Execution Vulnerability | |
| CVE-2020-17143 | High (8.8) | Elevated likelihood (71%) | Microsoft Exchange Server Information Disclosure Vulnerability | |
| CVE-2005-0560 | High (7.5) | Elevated likelihood (69%) | Heap-based buffer overflow in the SvrAppendReceivedChunk function in xlsasink.dll in the SMTP service of Exchange Server 2000 and 2003 allows remote attackers to execute arbitrary … | |
| CVE-2023-36757 | High (8.0) | Elevated likelihood (69%) | Microsoft Exchange Server Spoofing Vulnerability | |
| CVE-2007-0213 | Critical (10.0) | Elevated likelihood (66%) | Microsoft Exchange Server 2000 SP3, 2003 SP1 and SP2, and 2007 does not properly decode certain MIME encoded e-mails, which allows remote attackers to execute arbitrary code via a … | |
| CVE-2004-0574 | Critical (10.0) | Elevated likelihood (64%) | The Network News Transfer Protocol (NNTP) component of Microsoft Windows NT Server 4.0, Windows 2000 Server, Windows Server 2003, Exchange 2000 Server, and Exchange Server 2003 all… | |
| CVE-2018-0986 | High (8.8) | Elevated likelihood (63%) | A remote code execution vulnerability exists when the Microsoft Malware Protection Engine does not properly scan a specially crafted file, leading to memory corruption, aka "Micros… | |
| CVE-2017-8538 | High (7.8) | Elevated likelihood (50%) | 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 S… | |
| CVE-2017-8541 | High (7.8) | Elevated likelihood (50%) | 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 S… | |
| CVE-2020-17117 | Medium (6.6) | Elevated likelihood (49%) | Microsoft Exchange Remote Code Execution Vulnerability | |
| CVE-2008-1547 | Medium (4.3) | Elevated likelihood (48%) | Open redirect vulnerability in exchweb/bin/redir.asp in Microsoft Outlook Web Access (OWA) for Exchange Server 2003 SP2 (aka build 6.5.7638) allows remote attackers to redirect use… | |
| CVE-2020-16875 | High (8.4) | Elevated likelihood (47%) | <p>A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.</p> <p>An attacker who successfully exploited the vulne… | |
| CVE-2006-0002 | High (7.5) | Elevated likelihood (46%) | Unspecified vulnerability in Microsoft Outlook 2000 through 2003, Exchange 5.0 Server SP2 and 5.5 SP4, Exchange 2000 SP3, and Office allows remote attackers to execute arbitrary co… | |
| CVE-2007-0039 | High (7.8) | Elevated likelihood (45%) | The Exchange Collaboration Data Objects (EXCDO) functionality in Microsoft Exchange Server 2000 SP3, 2003 SP1 and SP2, and 2007 allows remote attackers to cause a denial of service… | |
| CVE-2005-1987 | High (7.5) | Elevated likelihood (44%) | Buffer overflow in Collaboration Data Objects (CDO), as used in Microsoft Windows and Microsoft Exchange Server, allows remote attackers to execute arbitrary code when CDOSYS or CD… | |
| CVE-2022-23277 | High (8.8) | Elevated likelihood (41%) | Microsoft Exchange Server Remote Code Execution Vulnerability |
Vulnerability data from the NVD andCISA KEV(US Government, public domain); Australian advisories fromASD’s ACSC (CC BY 4.0). Exploit-probability scores from FIRST EPSS.
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