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Vulnerability Intelligence

CVE-2021-26855 | Mondoo Vulnerability Intelligence

Vulnerability IntelligenceCVE-2021-26855

CVE-2021-26855

CRITICAL9.1

Microsoft Exchange Server Remote Code Execution Vulnerability

Published Mar 2, 2021

Modified 4 months ago

References

http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html

http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html

http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html

http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855

https://www.cve.org/CVERecord?id=CVE-2021-26855

CVSS Analysis

CVSS v3.1

9.1

Exploitability

Attack Vector

NetworkAV:N

Attack Complexity

LowAC:L

Privileges Required

NonePR:N

User Interaction

NoneUI:N

Scope

Scope

UnchangedS:U

Impact

Confidentiality

HighC:H

Integrity

HighI:H

Availability

NoneA:N

9.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Ecosystems

Timeline

PublishedMar 2, 2021

ModifiedOct 21, 2025