Heap-based buffer overflow in Microsoft products - CVE-2026-80085
Published: September 9, 2026
Vulnerability identifier: #VU148257
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-2026-80085
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 opening and saving or converting a specially crafted Word document. A remote attacker can send a specially crafted Word document to a target user to execute arbitrary code.
User interaction is required to open the document and save or convert it to another format. 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-2026-80085
Install security update from vendor's website.
Microsoft Word - update to 16.0.5569.1000
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