CVE-2026-21253
Severity CVSS v4.0:
Pending analysis
Type:
CWE-416
Use After Free
Publication date:
10/02/2026
Last modified:
27/03/2026
Description
Use after free in Mailslot File System allows an authorized attacker to elevate privileges locally.
Impact
Base Score 3.x
7.00
Severity 3.x
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:* | 10.0.14393.8868 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:* | 10.0.14393.8868 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* | 10.0.17763.8389 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* | 10.0.17763.8389 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:* | 10.0.19044.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:* | 10.0.19044.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:* | 10.0.19044.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:* | 10.0.19045.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:* | 10.0.19045.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:* | 10.0.19045.6937 (excluding) | |
| cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* | 10.0.22631.6649 (excluding) | |
| cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* | 10.0.22631.6649 (excluding) | |
| cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* | 10.0.26100.7781 (excluding) | |
| cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* | 10.0.26100.7781 (excluding) | |
| cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* | 10.0.26200.7781 (excluding) |
To consult the complete list of CPE names with products and versions, see this page
References to Advisories, Solutions, and Tools
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21253
- https://www.vicarius.io/vsociety/posts/cve-2026-21253-detection-script-elevation-of-privilege-vulnerability-in-mailslot-file-system
- https://www.vicarius.io/vsociety/posts/cve-2026-21253-mitigation-script-elevation-of-privilege-vulnerability-in-mailslot-file-system



