Heap-based buffer overflow in Microsoft Windows and Windows Server - CVE-2026-85880
Published: September 8, 2026
Vulnerability identifier: #VU147471
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H]
CVE-ID: CVE-2026-85880
CWE-ID: CWE-122
Exploitation vector: Local access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error in Windows ALPC. A local user can trigger a heap-based buffer overflow and execute arbitrary code with SYSTEM privileges.
Note, the vulnerability is being actively exploited in the wild.
Affected software
Microsoft Windows
Windows Server
Windows Server
How to mitigate CVE-2026-85880
Install updates from vendor's website.
Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7725, 10 22H2 10.0.19045.7725, 10 1607 10.0.14393.9512, 10 1809 10.0.17763.9245
Windows Server - addressed in versions 2012 R2 6.3.9600.23397, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622
Windows Server - addressed in versions 2012 R2 6.3.9600.23397, 2012 6.2.9200.26349, 2016 10.0.14393.9512, 2019 10.0.17763.9245, 2022 10.0.20348.5622