Heap-based buffer overflow in Microsoft Word and Microsoft Office - CVE-2026-69556
Published: September 8, 2026
Vulnerability identifier: #VU147795
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-2026-69556
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 a specially crafted document. A remote attacker can convince a user to open and interact with a specially crafted document to execute arbitrary code.
Affected software
Microsoft Word
Microsoft Office
Microsoft Office
How to mitigate CVE-2026-69556
Install security update from vendor's website.
Microsoft Word - update to 16.0.5569.1002
Microsoft Office - update to 16.0.17932.20960
Microsoft Office - update to 16.0.17932.20960