Buffer overflow in Microsoft Windows 10 Version 21h2
CVE-2026-83736
Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
- Microsoft Windows 10 Version 21h2
- Microsoft Windows 10 Version 22h2
- Microsoft Windows 11 Version 23h2
- Microsoft Windows 11 Version 24h2
- Microsoft Windows 11 Version 25h2
- Microsoft Windows 11 Version 26h1
- Microsoft Windows 11 Version 26h2
- Microsoft Windows Server 2022
- Microsoft Windows Server 2025
- Microsoft Windows Server 2025 (Server Core Installation)
Weakness classification (CWE)
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83736 (vendor-advisory, patch)
Frequently asked questions
- What is CVE-2026-83736?
- CVE-2026-83736 is a medium-severity vulnerability in Microsoft Windows 10 Version 21h2, classified under Heap-based Buffer Overflow. CVSS score: 5.5/10. Published 2026-10-13.
- How severe is CVE-2026-83736?
- Medium severity. CVSS v3 base score is 5.5 out of 10.