What is CVE-2026-62870?

CVE-2026-62870 is a high-severity vulnerability in Microsoft 365 Apps For Enterprise, classified under Use After Free. CVSS score: 8.8/10. Published 2026-08-04.

How severe is CVE-2026-62870?

High severity. CVSS v3 base score is 8.8 out of 10.

Use After Free in Microsoft 365 Apps For Enterprise

CVE-2026-62870

Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

Vulnerability class: Use-After-Free

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Microsoft 365 Apps For Enterprise — versions 16.0.1
Microsoft Excel 2016 — versions 16.0.0.0
Microsoft Office 2019 — versions 19.0.0
Microsoft Office Ltsc 2021 — versions 16.0.1
Microsoft Office Ltsc 2024 — versions 16.0.0

Weakness classification (CWE)

CWE-416 — Use After Free

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-62870?: CVE-2026-62870 is a high-severity vulnerability in Microsoft 365 Apps For Enterprise, classified under Use After Free. CVSS score: 8.8/10. Published 2026-08-04.
How severe is CVE-2026-62870?: High severity. CVSS v3 base score is 8.8 out of 10.