Buffer overflow in Microsoft 365 Apps For Enterprise
CVE-2026-66810
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
Vulnerability class: Buffer Overflow
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Office 2019 — versions 19.0.0
- Microsoft Office 365 For Mac — versions 1.0.0
- Microsoft Office Ltsc 2021 — versions 16.0.1
- Microsoft Office Ltsc 2024 — versions 16.0.0
- Microsoft Office Ltsc For Mac 2021 — versions 16.0.1
- Microsoft Office Ltsc For Mac 2024 — versions 16.0.0
- Microsoft Word 2016 — versions 16.0.1
Weakness classification (CWE)
References
- Microsoft Office Word Information Disclosure Vulnerability (vendor-advisory, patch)
Frequently asked questions
- What is CVE-2026-66810?
- CVE-2026-66810 is a medium-severity vulnerability in Microsoft 365 Apps For Enterprise, classified under Heap-based Buffer Overflow. CVSS score: 5.5/10. Published 2026-08-11.
- How severe is CVE-2026-66810?
- Medium severity. CVSS v3 base score is 5.5 out of 10.