What’s Vulnerable › Vulnerabilities

CVE-2023-33131: Microsoft Outlook Remote Code Execution Vulnerability

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-06-13 · updated 2026-06-17
• Weakness: CWE-94

Description

Microsoft Outlook Remote Code Execution Vulnerability

Affected products

• Microsoft Office: 2019
• Microsoft Office LTSC for Mac 2021: 2021
• Microsoft Outlook: 2013-sp1, 2016
• Microsoft Outlook Rt: 2013-sp1
• Microsoft 365 Apps: from 16.0.1 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Office LTSC 2021: from 16.0.1 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Outlook 2013: from 14.0.0 before 15.0.5563.1000 — fixed in 15.0.5563.1000
• Microsoft Outlook 2013 Service Pack 1: from 15.0.0.0 before 15.0.5563.1000 — fixed in 15.0.5563.1000
• Microsoft Office: from 19.0.0 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Outlook 2016 for Mac: from 16.0.0.0 before 16.0.5400.1000 — fixed in 16.0.5400.1000

How to fix

Upgrade to a fixed version: Microsoft 365 Apps https://aka.ms/OfficeSecurityReleases; Microsoft Office LTSC 2021 https://aka.ms/OfficeSecurityReleases; Microsoft Outlook 2013 15.0.5563.1000; Microsoft Outlook 2013 Service Pack 1 15.0.5563.1000; Microsoft Office https://aka.ms/OfficeSecurityReleases; Microsoft Outlook 2016 for Mac 16.0.5400.1000. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-33131
• http://packetstormsecurity.com/files/173361/Microsoft-365-MSO-2306-Build-16.0.16529.20100-Remote-Code-Execution.html
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-33131

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