CVE-2026-21251
Analyzed
Analyzed - Analysis Complete
Use-After-Free in Windows Cluster Client Failover Enables Local Privilege Escalation
Publication date: 2026-02-10
Last updated on: 2026-02-11
Assigner: Microsoft Corporation
Description
Description
Use after free in Windows Cluster Client Failover allows an authorized attacker to elevate privileges locally.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| microsoft | windows_server_2016 | to 10.0.14393.8868 (exc) |
| microsoft | windows_server_2019 | to 10.0.17763.8389 (exc) |
| microsoft | windows_server_2022 | to 10.0.20348.4711 (exc) |
| microsoft | windows_server_2025 | to 10.0.26100.32313 (exc) |
| microsoft | windows_server_2022_23h2 | to 10.0.25398.2149 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
