Vulnerability Description
Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally.
CVSS Score
7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | 365 Apps | - |
| Microsoft | Microsoft 365 | - |
| Microsoft | Office 2016 | - |
| Microsoft | Office 2019 | - |
| Microsoft | Office 2021 | - |
| Microsoft | Office 2024 | - |
Related Weaknesses (CWE)
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64909PatchVendor Advisory
FAQ
What is CVE-2026-64909?
CVE-2026-64909 is a vulnerability with a CVSS score of 7.8 (HIGH). Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally.
How severe is CVE-2026-64909?
CVE-2026-64909 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64909?
Check the references section above for vendor advisories and patch information. Affected products include: Microsoft 365 Apps, Microsoft Microsoft 365, Microsoft Office 2016, Microsoft Office 2019, Microsoft Office 2021.