CVE-2026-21253

HIGH

7.0

Description

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

CVE Details

CVSS v3.1 Score7.0

SeverityHIGH

CVSS VectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack VectorLOCAL

ComplexityHIGH

Privileges RequiredLOW

User InteractionNONE

Published2/10/2026

Last Modified3/27/2026

Sourcenvd

Honeypot Sightings0

Affected Products

microsoft:windows_10_1607microsoft:windows_10_1809microsoft:windows_10_21h2microsoft:windows_10_22h2microsoft:windows_11_23h2microsoft:windows_11_24h2microsoft:windows_11_25h2microsoft:windows_server_2012microsoft:windows_server_2016microsoft:windows_server_2019microsoft:windows_server_2022microsoft:windows_server_2022_23h2microsoft:windows_server_2025

Weaknesses (CWE)

CWE-416

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21253(secure@microsoft.com)

https://www.vicarius.io/vsociety/posts/cve-2026-21253-detection-script-elevation-of-privilege-vulnerability-in-mailslot-file-system(af854a3a-2127-422b-91ae-364da2661108)

https://www.vicarius.io/vsociety/posts/cve-2026-21253-mitigation-script-elevation-of-privilege-vulnerability-in-mailslot-file-system(af854a3a-2127-422b-91ae-364da2661108)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.