Every CVE Search/ Get API key

CVE-2021-27065

Microsoft Exchange Server Remote Code Execution Vulnerability

7.8 HighIn KEVPublic exploit

Microsoft Exchange Server Remote Code Execution Vulnerability

Attack profile

How easy it is to exploit

Attack vector
Local
Complexity
Low
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
High

Exploit likelihood

99.9%Up 15.8 points since Apr 14, 2021
90%50%10%1%

What each source reports

CVE List Score used 7.8

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability

Record
CVE-2021-27065
CVSS 3.1
7.8 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Weakness
CWE-22
Updated
2026-11-02
EUVDEUVD-2021-13836 7.8

Microsoft Exchange Server Remote Code Execution Vulnerability

Record
EUVD-2021-13836
CVSS 3.1
7.8 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Updated
2026-11-02
GitHub AdvisoriesGHSA-rwm8-8c4x-v87q 7.8

Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021...

Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26857, CVE-2021-26858, CVE-2021-27078.

Record
GHSA-rwm8-8c4x-v87q
CVSS 3.1
7.8 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness
CWE-22
Updated
2026-11-02
CISA KEV No score

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.

Record
CVE-2021-27065
Weakness
CWE-39
Updated
2026-11-02
NVD 7.8

Microsoft Exchange Server Remote Code Execution Vulnerability

Record
CVE-2021-27065
CVSS 3.1
7.8 HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.0
6.8 MediumAV:N/AC:M/Au:N/C:P/I:P/A:P
Weakness
CWE-22
Updated
2026-11-02

Affected products

Show 14 moreShow less

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
SourceLinkDate
MetasploitMicrosoft Exchange ProxyLogon RCE2021-03-02
PoC in GitHubadamrpostjr/cve-2021-270652021-03-06
Exploit-DBMicrosoft Exchange 2019 - Server-Side Request Forgery (Proxylogon) (PoC)2021-03-11

History

History
RecordedChangedSources
exploitation, exploits
first indexedCVE List, EUVD, Exploit-DB, GitHub Advisories, CISA KEV, Metasploit, NVD, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-27065 is a high vulnerability (CVSS 7.8) in Microsoft Exchange Server, published March 2, 2021. CISA lists it as known to be exploited, since November 3, 2021. EUVD reports exploitation since November 3, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 99.9%, the 99th percentile. No source names a fixed version.

References

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open