Elevation of Privilege Vulnerability in Mailslot File System by Microsoft
CVE-2026-21253

7HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1607
Windows 10 Version 1809
Windows 10 Version 21h2
Windows 10 Version 22h2
Vendor
CVE Published:
10 February 2026

What is CVE-2026-21253?

A vulnerability exists in the Mailslot File System where an attacker with authorized access can exploit a use after free condition, allowing them to potentially elevate privileges within the system. This flaw necessitates immediate attention to ensure proper security measures are in place to mitigate any unauthorized access.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8868

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8389

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.6937

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.