CVE-2026-64909
HIGHCVSS 7.8/10
Last modified
CVE-2026-64909 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally..
Description
Integer underflow (wrap or wraparound) in Microsoft Office allows an unauthorized attacker to execute code locally.
Metrics
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | >= 16.0.1, < https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office 2016 | >= 16.0.0, < 16.0.5565.1001 |
| Microsoft | Microsoft Office 2019 | >= 19.0.0, < https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office 365 for Mac | >= 1.0.0, < 16.112.26081010 |
| Microsoft | Microsoft Office LTSC 2021 | >= 16.0.1, < https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC 2024 | >= 16.0.0, < https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC for Mac 2021 | >= 16.0.1, < 16.112.26081010 |
| Microsoft | Microsoft Office LTSC for Mac 2024 | >= 16.0.0, < 16.112.26081010 |
References
Timeline
- Published
- Last Modified
- Status
- Undergoing Analysis
Frequently Asked Questions
What is CVE-2026-64909?
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 a CVSS score of 7.8/10 (HIGH severity).
How do I fix CVE-2026-64909?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-64909?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST