Out-of-bounds read in Windows Server - CVE-2026-108421
Published: November 10, 2026
Vulnerability identifier: #VU164721
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-108421
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to escalate privileges on an affected Windows Server system.
The vulnerability exists due to an out-of-bounds read in Windows File Server Resource Management Service when handling network-supplied input. A remote attacker can supply crafted input that, with user interaction, triggers a read beyond the intended memory boundaries to escalate privileges.
Affected software
Windows Server
How to mitigate CVE-2026-108421
Install security update from vendor's website.
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