Use After Free in Microsoft Windows_11_24h2
CVE-2026-20854
Use after free in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to execute code over a network.
Vulnerability class: Use-After-Free
EPSS: 0.010 (59.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Microsoft Windows_11_24h2
- Microsoft Windows_11_25h2
- Microsoft Windows 11 Version 24h2 — versions 10.0.26100.0
- Microsoft Windows 11 Version 25h2 — versions 10.0.26200.0
- Microsoft Windows Server 2025 — versions 10.0.26100.0
- Microsoft Windows_server_2025
- Microsoft Windows Server 2025 (Server Core Installation) — versions 10.0.26100.0
Weakness classification (CWE)
References
- secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20854?
- CVE-2026-20854 is a high-severity vulnerability in Microsoft Windows_11_24h2, classified under Use After Free. CVSS score: 7.5/10. Published 2026-01-13.
- How severe is CVE-2026-20854?
- High severity. CVSS v3 base score is 7.5 out of 10.