Use-after-free in Microsoft Windows and Windows Server - CVE-2026-62819

Vulnerability identifier: #VU141782

CSH Severity: High

CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-62819

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to use-after-free in Windows Routing and Remote Access Service (RRAS) when handling specially crafted network packets. A remote attacker can send a specially crafted packet to the affected service to execute arbitrary code.

Successful exploitation requires winning a race condition. No user interaction is required.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7663, 10 22H2 10.0.19045.7663, 10 1607 10.0.14393.9418, 10 1809 10.0.17763.9115, 11 23H2 10.0.22631.7517, 11 24H2 10.0.26100.9106, 11 24H2 10.0.26100.9168, 11 25H2 10.0.26200.9168, 11 26H1 10.0.28000.2704
Windows Server - addressed in versions 2012 R2 6.3.9600.23337, 2012 6.2.9200.26279, 2016 10.0.14393.9418, 2019 10.0.17763.9115, 2022 10.0.20348.5440, 2022 10.0.20348.5499, 2025 10.0.26100.33222, 2025 10.0.26100.33296

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-62819
• https://support.microsoft.com/help/5120238

• Multiple vulnerabilities in Microsoft Windows