What is CVE-2026-83931?

CVE-2026-83931 is a high-severity vulnerability in Microsoft Windows 11 Version 23h2, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-10-13.

How severe is CVE-2026-83931?

High severity. CVSS v3 base score is 7.8 out of 10.

Buffer overflow in Microsoft Windows 11 Version 23h2

CVE-2026-83931

Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

Vulnerability class: Buffer Overflow

Published 2026-10-13 · last modified 2026-10-13.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

Windows Hyper-V Remote Code Execution Vulnerability (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-83931?: CVE-2026-83931 is a high-severity vulnerability in Microsoft Windows 11 Version 23h2, classified under Heap-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-10-13.
How severe is CVE-2026-83931?: High severity. CVSS v3 base score is 7.8 out of 10.