Use After Free in Microsoft Windows 10 21h2
CVE-2026-20871
Use after free in Desktop Windows Manager allows an authorized attacker to elevate privileges locally.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.042 (90.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 90.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.041 · newest: 0.042 · change: +0.001
Affected products
- Microsoft Windows 10 21h2
- Microsoft Windows 10 22h2
- Microsoft Windows 10 Version 21h2 — versions 10.0.19044.0
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
- 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
Weakness classification (CWE)
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20871 (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20871?
- CVE-2026-20871 is a high-severity vulnerability in Microsoft Windows 10 21h2, classified under Use After Free. CVSS score: 7.8/10. Published 2026-01-13.
- How severe is CVE-2026-20871?
- High severity. CVSS v3 base score is 7.8 out of 10.