CVE-2026-70111

Name of the Vulnerable Software and Affected Versions Windows Server 2019 Windows Server 2022 Windows Server 2025

Description An untrusted pointer dereference in the Windows Kernel, specifically within the mup.sys driver, allows an unauthorized attacker to cause a denial-of-service or elevate privileges over a network. An attacker can coerce an affected server to connect to a rogue server that returns a malformed DFS referral response. When mup.sys processes this response via internal SMB traffic, it triggers a null dereference crash, leading to a system crash.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.