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NVD Vulnerability Details :
CVE-2026-21253
Modified
More InfoOfficial Page
Source-secure@microsoft.com
View Known Exploited Vulnerability (KEV) details
Published At-10 Feb, 2026 | 18:16
Updated At-27 Mar, 2026 | 21:17

Use after free in Mailslot File System allows an authorized attacker to elevate privileges locally.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Secondary3.17.0HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Type: Secondary
Version: 3.1
Base score: 7.0
Base severity: HIGH
Vector:
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CPE Matches
Microsoft Corporation
microsoft
>>windows_10_1607>>Versions before 10.0.14393.8868(exclusive)
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_10_1607>>Versions before 10.0.14393.8868(exclusive)
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
Microsoft Corporation
microsoft
>>windows_10_1809>>Versions before 10.0.17763.8389(exclusive)
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_10_1809>>Versions before 10.0.17763.8389(exclusive)
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
Microsoft Corporation
microsoft
>>windows_10_21h2>>Versions before 10.0.19044.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
Microsoft Corporation
microsoft
>>windows_10_21h2>>Versions before 10.0.19044.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_10_21h2>>Versions before 10.0.19044.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
Microsoft Corporation
microsoft
>>windows_10_22h2>>Versions before 10.0.19045.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
Microsoft Corporation
microsoft
>>windows_10_22h2>>Versions before 10.0.19045.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_10_22h2>>Versions before 10.0.19045.6937(exclusive)
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
Microsoft Corporation
microsoft
>>windows_11_23h2>>Versions before 10.0.22631.6649(exclusive)
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
Microsoft Corporation
microsoft
>>windows_11_23h2>>Versions before 10.0.22631.6649(exclusive)
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_11_24h2>>Versions before 10.0.26100.7781(exclusive)
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
Microsoft Corporation
microsoft
>>windows_11_24h2>>Versions before 10.0.26100.7781(exclusive)
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_11_25h2>>Versions before 10.0.26200.7781(exclusive)
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
Microsoft Corporation
microsoft
>>windows_11_25h2>>Versions before 10.0.26200.7781(exclusive)
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
Microsoft Corporation
microsoft
>>windows_server_2012>>-
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
Microsoft Corporation
microsoft
>>windows_server_2012>>r2
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
Microsoft Corporation
microsoft
>>windows_server_2016>>Versions before 10.0.14393.8868(exclusive)
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:-:*:x64:*
Microsoft Corporation
microsoft
>>windows_server_2019>>Versions before 10.0.17763.8389(exclusive)
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:-:*:x64:*
Microsoft Corporation
microsoft
>>windows_server_2022>>Versions before 10.0.20348.4711(exclusive)
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:-:*:x64:*
Microsoft Corporation
microsoft
>>windows_server_2022_23h2>>Versions before 10.0.25398.2149(exclusive)
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:-:*:x64:*
Microsoft Corporation
microsoft
>>windows_server_2025>>Versions before 10.0.26100.32313(exclusive)
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*
Weaknesses
CWE IDTypeSource
CWE-416Secondarysecure@microsoft.com
CWE ID: CWE-416
Type: Secondary
Source: secure@microsoft.com
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21253secure@microsoft.com
Vendor Advisory
https://www.vicarius.io/vsociety/posts/cve-2026-21253-detection-script-elevation-of-privilege-vulnerability-in-mailslot-file-systemaf854a3a-2127-422b-91ae-364da2661108
N/A
https://www.vicarius.io/vsociety/posts/cve-2026-21253-mitigation-script-elevation-of-privilege-vulnerability-in-mailslot-file-systemaf854a3a-2127-422b-91ae-364da2661108
N/A
Hyperlink: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21253
Source: secure@microsoft.com
Resource:
Vendor Advisory
Hyperlink: https://www.vicarius.io/vsociety/posts/cve-2026-21253-detection-script-elevation-of-privilege-vulnerability-in-mailslot-file-system
Source: af854a3a-2127-422b-91ae-364da2661108
Resource: N/A
Hyperlink: https://www.vicarius.io/vsociety/posts/cve-2026-21253-mitigation-script-elevation-of-privilege-vulnerability-in-mailslot-file-system
Source: af854a3a-2127-422b-91ae-364da2661108
Resource: N/A
Change History
0Changes found
Details not found