CVE-2026-66799
HIGHCVSS 7.8/10EPSS 0.27%
Last modified
CVE-2026-66799 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Heap-based buffer overflow in Windows Key Guard allows an authorized attacker to elevate privileges locally.. EPSS estimates a 0.27% chance of exploitation in the next 30 days.
Description
Heap-based buffer overflow in Windows Key Guard allows an authorized attacker to elevate privileges locally.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 10 1607 | < 10.0.14393.9418 |
| Microsoft | Windows 10 1809 | < 10.0.17763.9115 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7663 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7663 |
| Microsoft | Windows 11 23h2 | < 10.0.22631.7517 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.9106 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.9106 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2704 |
| Microsoft | Windows Server 2012 | All versions |
| Microsoft | Windows Server 2012 | r2 |
| Microsoft | Windows Server 2016 | < 10.0.14393.9418 |
| Microsoft | Windows Server 2019 | < 10.0.17763.9115 |
| Microsoft | Windows Server 2022 | < 10.0.20348.5440 |
| Microsoft | Windows Server 2025 | < 10.0.26100.33222 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66799Patch, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-66799?
Heap-based buffer overflow in Windows Key Guard allows an authorized attacker to elevate privileges locally.
How severe is CVE-2026-66799?
CVE-2026-66799 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.
How do I fix CVE-2026-66799?
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-2026-66799?
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Scan your code nowSource: NVD / NIST