Heap-based buffer overflow in Microsoft products - CVE-2026-55125
Published: July 17, 2026
Vulnerability identifier: #VU138199
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-2026-55125
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 trick the victim into opening a specially crafted file to execute arbitrary code.
User interaction is required to open the crafted file, and the Preview Pane is not an attack vector.
Affected software
Microsoft Office for macOS
Microsoft Office
Microsoft SharePoint Server
Microsoft Office
Microsoft SharePoint Server
How to mitigate CVE-2026-55125
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.111.26071215
Microsoft Office - update to 16.0.5561.1000
Microsoft SharePoint Server - addressed in versions 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434
Microsoft Office - update to 16.0.5561.1000
Microsoft SharePoint Server - addressed in versions 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434