Out-of-bounds read in Microsoft products - CVE-2026-124179
Published: November 11, 2026
Vulnerability identifier: #VU165493
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-124179
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose information from heap memory.
The vulnerability exists due to an out-of-bounds read in Microsoft Office Excel when processing a malicious Office file. A remote attacker can send a specially crafted Office file to a user and convince them to open it to potentially read small portions of heap memory.
The Preview Pane is not an attack vector.
Affected software
Microsoft Office for macOS
Microsoft Office
Office Online Server
Microsoft Office
Office Online Server
How to mitigate CVE-2026-124179
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.115.26110837
Office Online Server - update to 16.0.10417.20236
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140
Office Online Server - update to 16.0.10417.20236
Microsoft Office - addressed in versions 16.0.14334.21048, 16.0.17932.21140