Heap-based buffer overflow in Microsoft products - CVE-2026-69629
Published: September 8, 2026
Vulnerability identifier: #VU147861
CSH Severity: High
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-69629
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute code.
The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Outlook when opening a specially crafted file. A remote attacker can trick a victim into opening a specially crafted file to execute code.
The Preview Pane is also an attack vector.
Affected software
Microsoft 365 Apps for Enterprise
Microsoft Outlook
Microsoft Office
Microsoft Outlook
Microsoft Office
How to mitigate CVE-2026-69629
Install security update from vendor's website.
Microsoft 365 Apps for Enterprise - update to 16.0.20326.20138
Microsoft Outlook - update to 16.0.5569.1002
Microsoft Office - addressed in versions 16.0.10417.20207, 16.0.14334.20906, 16.0.17932.20976
Microsoft Outlook - update to 16.0.5569.1002
Microsoft Office - addressed in versions 16.0.10417.20207, 16.0.14334.20906, 16.0.17932.20976