Integer overflow in Microsoft Excel
CVE-2026-44803
Integer overflow or wraparound in Windows Win32K - GRFX allows an unauthorized attacker to execute code locally.
Vulnerability class: Integer Overflow
EPSS: 0.005 (41.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Microsoft Excel
- Microsoft Excel For Android — versions 16.0.0.0
- Microsoft Powerpoint For Android — versions 16.0.0.0
- Microsoft Word For Android — versions 16.0.0.0
- Microsoft Powerpoint
- Microsoft Windows_10_1607
- Microsoft Windows_10_1809
- Microsoft Windows_10_21h2
- Microsoft Windows_10_22h2
- Microsoft Windows 10 Version 1607 — versions 10.0.14393.0
Weakness classification (CWE)
References
- secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-44803?
- CVE-2026-44803 is a high-severity vulnerability in Microsoft Excel, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2026-06-09.
- How severe is CVE-2026-44803?
- High severity. CVSS v3 base score is 7.8 out of 10.