Heap-based buffer overflow in Microsoft Office 365 for Mac and Microsoft Office LTSC - CVE-2026-102858
Published: October 13, 2026
Vulnerability identifier: #VU154261
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-102858
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 on the target system.
The vulnerability exists due to a boundary error in Microsoft Office OneNote. A remote attacker can trick a victim to open a specially crafted file, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Affected software
Microsoft Office 365 for Mac
Microsoft Office LTSC
Microsoft Office LTSC
How to mitigate CVE-2026-102858
Install updates from vendor's website.