Heap-based buffer overflow in Microsoft Office for macOS and Microsoft Office - CVE-2026-63533
Published: August 12, 2026
Vulnerability identifier: #VU141943
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-2026-63533
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 heap-based buffer overflow in Microsoft Office for macOS when parsing a crafted Office file. A remote attacker can send a specially crafted Office file to execute arbitrary code.
User interaction is required to open or preview the crafted file, and the Preview Pane is an attack vector.
Affected software
Microsoft Office for macOS
Microsoft Office
Microsoft Office
How to mitigate CVE-2026-63533
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.112.26081010
Microsoft Office - update to 16.0.5565.1001
Microsoft Office - update to 16.0.5565.1001