Numeric Truncation Error in Microsoft Windows and Windows Server - CVE-2026-119988

Vulnerability identifier: #VU165400

CSH Severity: Low

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-2026-119988

CWE-ID: CWE-197

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to execute arbitrary code on an affected system.

The vulnerability exists due to a numeric truncation error in Windows SMB when processing network traffic. A remote user can supply specially crafted SMB traffic to execute arbitrary code, with successful exploitation requiring user interaction.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7846, 10 22H2 10.0.19045.7846, 10 1607 10.0.14393.9688, 10 1809 10.0.17763.9487, 11 23H2 10.0.22631.7711, 11 24H2 10.0.26100.9911, 11 24H2 10.0.26100.9974, 11 25H2 10.0.26200.9911, 11 25H2 10.0.26200.9974, 11 26H1 10.0.28000.3501
Windows Server - addressed in versions 2016 10.0.14393.9688, 2019 10.0.17763.9487, 2022 10.0.20348.5870, 2025 10.0.26100.33730, 2025 10.0.26100.33822

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-119988

• Multiple vulnerabilities in Microsoft Windows