Forwarded National Information Sharing and Analysis Center Information Security Alert NISAC-200-202608-00000002

[Content Description]
Researchers discovered that Microsoft Excel contains a Use After Free vulnerability (CVE-2026-62870). An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary code. Please promptly verify and perform patching.

[Impacted Platform]
Microsoft 365 Apps for Enterprise for 32-bit Systems

Microsoft 365 Apps for Enterprise for 64-bit Systems

Microsoft Excel 2016 (32-bit edition) versions prior to 16.0.5561.1001

Microsoft Excel 2016 (64-bit edition) versions prior to 16.0.5561.1001

Microsoft Office 2019 for 32-bit editions

Microsoft Office 2019 for 64-bit editions

Microsoft Office LTSC 2021 for 32-bit editions

Microsoft Office LTSC 2021 for 64-bit editions

Microsoft Office LTSC 2024 for 32-bit editions

Microsoft Office LTSC 2024 for 64-bit editions

[Recommended Actions]
The official has released a security update for the vulnerability. Please refer to the official instructions for updates. The URL is as follows: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62870

[Reference]
1. https://nvd.nist.gov/vuln/detail/CVE-2026-62870
2. https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62870