Vulnerability in Microsoft 365 Apps
CVE-2026-65807
Access of resource using incompatible type ('type confusion') in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.008 (55.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.008 · change: +0.004
Affected products
- Microsoft 365 Apps
- Microsoft Excel — versions 2016
- Microsoft 365
- 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 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
Weakness classification (CWE)
References
- Microsoft Excel Remote Code Execution Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-65807?
- CVE-2026-65807 is a high-severity vulnerability in Microsoft 365 Apps, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 8.8/10. Published 2026-08-11.
- How severe is CVE-2026-65807?
- High severity. CVSS v3 base score is 8.8 out of 10.