CVE-2026-40358: Microsoft Office Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
Other sources
Microsoft Office Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5552.1000Patch KB5002866 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in https://aka.ms/OfficeSecurityReleases - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.109.26051019
Event History
Frequently Asked Questions
What is the severity of CVE-2026-40358?
The severity of CVE-2026-40358 is high, with a score of 8.4.
How do I fix CVE-2026-40358?
To fix CVE-2026-40358, update Microsoft Office to the latest version provided by Microsoft.
What is the impact of CVE-2026-40358?
CVE-2026-40358 allows an unauthorized attacker to execute code locally on affected systems.
Which software is affected by CVE-2026-40358?
CVE-2026-40358 affects various versions of Microsoft Office, including Microsoft Office 2016 and Microsoft 365 Apps.
What type of vulnerability is CVE-2026-40358?
CVE-2026-40358 is classified as a Use After Free vulnerability.