Integer overflow in Microsoft products - CVE-2026-55026
Published: July 17, 2026
Vulnerability identifier: #VU138201
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-55026
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to integer overflow or wraparound in Microsoft Office for macOS when parsing a crafted file. A remote attacker can trick the victim into opening a specially crafted file to disclose sensitive information.
The disclosed information is limited to small portions of heap memory. 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-2026-55026
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