CVE-2026-55949: Microsoft Excel Remote Code Execution Vulnerability
Microsoft Excel Remote Code Execution Vulnerability
Other sources
Use of uninitialized resource 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 16.0.5561.1001Patch KB5002886 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.111.26071215 - 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 16.0.10417.20175Patch KB5002884
Event History
Frequently Asked Questions
What is the severity of CVE-2026-55949?
CVE-2026-55949 has a severity rating of high, with a score of 7.8.
How do I fix CVE-2026-55949?
To fix CVE-2026-55949, ensure that you update Microsoft Excel and all related software to the latest version provided by Microsoft.
What types of software are affected by CVE-2026-55949?
CVE-2026-55949 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.
What can an attacker do by exploiting CVE-2026-55949?
An attacker exploiting CVE-2026-55949 can execute arbitrary code locally on the affected system.
Is user interaction required for CVE-2026-55949 to be exploited?
Yes, CVE-2026-55949 requires user interaction to be exploited, as it involves resources used by Microsoft Excel.