CVE-2026-78509
Microsoft Office Outlook Remote Code Execution vulnerability
MSRC advisory September 8, 2026
Alert details
- Source feed
- Microsoft MSRC
- CVE ID
- CVE-2026-78509
- Affected products
- Microsoft Office Outlook Remote Code Execution · Microsoft Microsoft Office Outlook Remote Code Execution · Microsoft
What happened
Microsoft is announcing the availability of the security updates for Microsoft Office for Mac. Customers running affected Mac software should install the update for their product to be protected from this vulnerability. Customers running other Microsoft Office software do not need to take any action. See the [Release Notes](https://go.microsoft.com/fwlink/p/?linkid=831049) for more information and download links.
What it means for your business
Microsoft Office Outlook Remote Code Execution vulnerability (CVE-2026-78509) was added to Microsoft’s security update guidance. Microsoft is announcing the availability of the security updates for Microsoft Office for Mac. Customers running affected Mac software should install the update for their product to be protected from this vulnerability. Customers running other Microsoft Office software do not… If you need help checking exposure, call (864) 335-9223.
Sources
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