CVE-2026-21251

published 2026-02-10

CVE-2026-21251: Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.

high 7.8 CVSS 3.1

AV L AC L PR L UI N S U C H I H A H

Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.

Affected

14 ranges

Vendor	Product	Version range	Fixed in
microsoft	windows_server_2016	< 10.0.14393.8868	10.0.14393.8868
microsoft	windows_server_2016	>= 10.0.14393.0 < 10.0.14393.8868	10.0.14393.8868
microsoft	windows_server_2019	< 10.0.17763.8389	10.0.17763.8389
microsoft	windows_server_2019	>= 10.0.17763.0 < 10.0.17763.8389	10.0.17763.8389
microsoft	windows_server_2022	< 10.0.20348.4711	10.0.20348.4711
microsoft	windows_server_2022	>= 10.0.20348.0 < 10.0.20348.4773	10.0.20348.4773
microsoft	windows_server_2022_23h2	< 10.0.25398.2149	10.0.25398.2149
microsoft	windows_server_2025	< 10.0.26100.32313	10.0.26100.32313
microsoft	windows_server_2025	>= 10.0.26100.0 < 10.0.26100.32370	10.0.26100.32370
msrc	windows_server_2016	—	—
msrc	windows_server_2019	—	—
msrc	windows_server_2022	—	—
msrc	windows_server_2022_23h2_edition	—	—
msrc	windows_server_2025	—	—

CWE-416