Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows and Windows Server - CVE-2025-29833

Vulnerability identifier: #VU109048

CSH Severity: Medium

CVSS v4: 7.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-29833

CWE-ID: CWE-367

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to a time-of-check, time-of-use (TOCTOU) race condition in Microsoft Virtual Machine Bus (VMBus). A remote user can execute arbitrary code on the target system.

Microsoft Windows
Windows Server

Install update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.5854, 10 22H2 10.0.19045.5854, 10 1507 10.0.10240.21014, 10 1607 10.0.14393.8066, 10 1809 10.0.17763.7314, 11 22H2 10.0.22621.5335, 11 23H2 10.0.22631.5335, 11 24H2 10.0.26100.3981, 11 24H2 10.0.26100.4061
Windows Server - addressed in versions 2012 R2 6.3.9600.22577, 2012 6.2.9200.25475, 2016 10.0.14393.8066, 2019 10.0.17763.7314, 2022 23H2 10.0.25398.1611, 2022 10.0.20348.3630, 2022 10.0.20348.3692, 2025 10.0.26100.3981, 2025 10.0.26100.4061

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2025-29833

• Remote code execution in Microsoft Virtual Machine Bus (VMBus)