Use-after-free in Microsoft Windows and Windows Server - CVE-2026-83997
Published: September 9, 2026
Vulnerability identifier: #VU148346
CSH Severity: High
CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83997
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use-after-free in Windows Message Queuing when processing a specially crafted packet sent to an affected service over the network. A remote attacker can send a specially crafted packet to execute arbitrary code.
Successful exploitation requires winning a race condition.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-83997
Install security update from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7725, 10 22H2 10.0.19045.7725, 11 23H2 10.0.22631.7582, 11 24H2 10.0.26100.9445, 11 25H2 10.0.26200.9445, 11 26H1 10.0.28000.2954
Windows Server - addressed in versions 2022 10.0.20348.5622, 2025 10.0.26100.33438
Windows Server - addressed in versions 2022 10.0.20348.5622, 2025 10.0.26100.33438