Out-of-bounds read in Office Online Server and Microsoft Office - CVE-2026-105718
Published: October 13, 2026
Vulnerability identifier: #VU154344
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-2026-105718
CWE-ID: CWE-125
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 an out-of-bounds read in Microsoft Office Excel when processing malicious Office files. A remote attacker can send a malicious Office file and convince the victim to open it to execute arbitrary code.
The Preview Pane is not an attack vector for this vulnerability.
Affected software
Office Online Server
Microsoft Office
Microsoft Office
How to mitigate CVE-2026-105718
Install security update from vendor's website.
Office Online Server - update to 16.0.10417.20228
Microsoft Office - addressed in versions 16.0.14334.20974, 16.0.17932.21056
Microsoft Office - addressed in versions 16.0.14334.20974, 16.0.17932.21056