Use-after-free in Windows SDK - CVE-2026-21219
Published: January 13, 2026
Vulnerability identifier: #VU121258
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-21219
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Windows SDK
Windows SDK
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a use-after-free error in Inbox COM Objects (Global Memory). A remote attacker can win a race condition and execute arbitrary code on the target system.
How to mitigate CVE-2026-21219
Install updates from vendor's website.