| CVE Number | Vulnerability | Product | Severity | Date |
|---|---|---|---|---|
| CVE-2026-78509 | Microsoft Office Outlook Remote Code Execution Vulnerability | Microsoft Office, Microsoft 365 | Critical | 15-10-2026 |
Technical Information
An unauthenticated attacker could exploit a heap-based buffer overflow vulnerability in Microsoft Outlook by sending a specially crafted email that triggers remote code execution when viewed in the Outlook’s Reading Pane, without requiring user interaction or authentication.
Patch release date: Sep 08, 2026
Further information on this vulnerability is available at : CVE-2026-78509
Affected Software
Microsoft Office 365 for Mac,Microsoft Office 2019 for 32-bit editions,
Microsoft Office 2019 for 64-bit editions,
Microsoft 365 Apps for Enterprise for 32-bit Systems,
Microsoft 365 Apps for Enterprise for 64-bit Systems,
Microsoft Office LTSC for Mac 2021,
Microsoft Office LTSC 2021 for 64-bit editions,
Microsoft Office LTSC 2021 for 32-bit editions,
Microsoft Office LTSC 2024 for 32-bit editions,
Microsoft Office LTSC 2024 for 64-bit editions,
Microsoft Office LTSC for Mac 2024,
Microsoft Word 2016 (32-bit edition),
Microsoft Word 2016 (64-bit edition)