Buffer overflow in Microsoft Windows 11 23h2
CVE-2026-20876
Heap-based buffer overflow in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to elevate privileges locally.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (41.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- Microsoft Windows 11 23h2
- Microsoft Windows 11 24h2
- Microsoft Windows 11 25h2
- Microsoft Windows 11 Version 22h3 — versions 10.0.22631.0
- Microsoft Windows 11 Version 23h2 — versions 10.0.22631.0
- Microsoft Windows 11 Version 24h2 — versions 10.0.26100.0
- Microsoft Windows 11 Version 25h2 — versions 10.0.26200.0
- Microsoft Windows Server 2022 23h2
- Microsoft Windows Server 2022, 23h2 Edition (Server Core Installation) — versions 10.0.25398.0
- Microsoft Windows Server 2025 — versions 10.0.26100.0
Weakness classification (CWE)
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876 (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20876?
- CVE-2026-20876 is a medium-severity vulnerability in Microsoft Windows 11 23h2, classified under Heap-based Buffer Overflow. CVSS score: 6.7/10. Published 2026-01-13.
- How severe is CVE-2026-20876?
- Medium severity. CVSS v3 base score is 6.7 out of 10.