CVE-2026-44820: Microsoft Excel Remote Code Execution Vulnerability
Microsoft Excel Remote Code Execution Vulnerability
Other sources
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
— 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 16.0.5556.1001Patch KB5002877 - 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 16.110.26061317 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.10417.20137Patch KB5002875
Event History
Frequently Asked Questions
What is the severity of CVE-2026-44820?
CVE-2026-44820 has a severity rating of high, with a score of 7.8.
How does CVE-2026-44820 affect Microsoft Excel?
CVE-2026-44820 allows an unauthorized attacker to execute remote code locally through an integer underflow in Microsoft Excel.
Which versions of Microsoft Excel are impacted by CVE-2026-44820?
CVE-2026-44820 affects Microsoft Excel 2016, Microsoft 365 Apps for Enterprise, Microsoft Office Online Server, Microsoft 365 Apps, Microsoft Office 2019, Microsoft Office 2021, and Microsoft Office 2024.
How do I fix CVE-2026-44820?
To fix CVE-2026-44820, users should apply the latest security updates provided by Microsoft for affected Excel versions.
What is the cause of CVE-2026-44820?
CVE-2026-44820 is caused by an integer underflow vulnerability in Microsoft Excel.