Remote Code Execution Vulnerability in Microsoft Office Outlook
CVE-2026-78519

8.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2019
Microsoft Office Ltsc 2021
Microsoft Office Ltsc 2024
Vendor
CVE Published:
8 September 2026

What is CVE-2026-78519?

A vulnerability in Microsoft Office Outlook arises from the use of an uninitialized resource, which can be exploited by an attacker to execute arbitrary code over a network. This flaw poses significant security risks as it can potentially lead to unauthorized access and data compromise. Organizations using the affected versions of Outlook should take immediate action to apply necessary updates and protect their systems.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1 < 16.0.20326.20138

Microsoft Office 2019 32-bit Systems 19.0.0 < 16.0.10417.20207

Microsoft Office LTSC 2021 32-bit Systems 16.0.1 < 16.0.14334.20906

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.