CVE-2026-78509
Microsoft Office Outlook Remote Code Execution Vulnerability
CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th
Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
| Vendor | microsoft |
| Product | microsoft 365 apps for enterprise |
| Ecosystems | |
| Industries | TechnologyEnterprise |
| Published | Sep 8, 2026 |
| Last Updated | Sep 15, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
Microsoft / Microsoft 365 Apps for Enterprise
16.0.1 < 16.0.20326.20138
Microsoft / Microsoft Office 2019
19.0.0 < 16.0.10417.20207
Microsoft / Microsoft Office 365 for Mac
-
Microsoft / Microsoft Office LTSC 2021
16.0.1 < 16.0.14334.20906
Microsoft / Microsoft Office LTSC 2024
16.0.0 < 16.0.17932.20976
Microsoft / Microsoft Office LTSC for Mac 2021
-
Microsoft / Microsoft Office LTSC for Mac 2024
-
Microsoft / Microsoft Word 2016
16.0.1 < 16.0.5569.1000