Main Vulnerability Database Vulnerabilities #VU165444

Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2026-121681

Published: November 11, 2026

Vulnerability identifier: #VU165444

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-121681

CWE-ID: CWE-122

Exploitation vector: Local access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to escalate privileges on the affected system.

The vulnerability exists due to a heap-based buffer overflow in Microsoft Trace Data Helper when processing data. A local user can trigger the overflow to corrupt heap memory and escalate privileges.

Affected software

Microsoft Windows
Windows Server

How to mitigate CVE-2026-121681

Install security update from vendor's website.

Microsoft Windows - addressed in versions 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Windows Server - update to 2025 10.0.26100.33822

External References

Related Security Bulletins