Use-after-free in Microsoft Windows and Windows Server - CVE-2026-113859

Vulnerability details

The vulnerability allows a remote attacker on the local network to execute arbitrary code on an affected system.

The vulnerability exists due to use-after-free in Windows TCP/IP when processing network traffic. A remote attacker on the local network can send specially crafted network traffic to trigger access to freed memory and execute arbitrary code.

Successful exploitation requires winning a race condition.

Affected software

How to mitigate CVE-2026-113859

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-113859
• https://support.microsoft.com/help/5132061

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Windows