Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2026-49796

Vulnerability identifier: #VU137973

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-2026-49796

CWE-ID: CWE-122

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to execute arbitrary code.

The vulnerability exists due to heap-based buffer overflow in Windows GDI+ when processing crafted content locally. A local user can execute crafted code on the local system to execute arbitrary code.

The issue is described as remote code execution in the title, but exploitation occurs locally.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7548, 10 22H2 10.0.19045.7548, 10 1607 10.0.14393.9339, 10 1809 10.0.17763.9020, 11 24H2 10.0.26100.8875, 11 25H2 10.0.26200.8875, 11 26H1 10.0.28000.2269, 11 26H1 10.0.28000.2525
Windows Server - addressed in versions 2012 R2 6.3.9600.23291, 2012 6.2.9200.26226, 2016 10.0.14393.9339, 2019 10.0.17763.9020, 2022 10.0.20348.5386, 2025 10.0.26100.33158

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-49796

• Multiple vulnerabilities in Microsoft Windows