Heap-based buffer overflow in Microsoft products - CVE-2026-69671
Published: September 8, 2026
Vulnerability identifier: #VU147875
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-2026-69671
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in Microsoft Office Word when processing a specially crafted document. A remote attacker can convince a user to open and interact with a specially crafted document to execute arbitrary code.
The Preview Pane is not an attack vector.
Affected software
Microsoft Word
Microsoft 365 Apps for Enterprise
Microsoft Office
Microsoft 365 Apps for Enterprise
Microsoft Office
How to mitigate CVE-2026-69671
Install security update from vendor's website.
Microsoft Word - update to 16.0.5569.1002
Microsoft 365 Apps for Enterprise - update to 16.0.20326.20138
Microsoft Office - addressed in versions 16.0.10417.20207, 16.0.14334.20906, 16.0.17932.20976
Microsoft 365 Apps for Enterprise - update to 16.0.20326.20138
Microsoft Office - addressed in versions 16.0.10417.20207, 16.0.14334.20906, 16.0.17932.20976