Use-after-free in Linux kernel - CVE-2026-72492

Vulnerability identifier: #VU142949

CSH Severity: Medium

CVSS v4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-72492

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to a use-after-free in same_client_has_lease() and smb_grant_oplock() when handling lease state for existing client oplocks during concurrent close operations. A remote user can trigger a concurrent close condition to cause a denial of service.

The issue occurs because a pointer selected from ci->m_op_list can be used after the last reference is dropped before it is dereferenced.

Linux kernel
Ubuntu
linux-nvidia (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• https://git.kernel.org/stable/c/09634cd055d9bd8dd167995ea52bcd8028dd5dac
• https://git.kernel.org/stable/c/0ff82a9cf9312678d8bc4edeef0b6e82659ac12a
• https://git.kernel.org/stable/c/35d3d6ff2bc1e7aaecb15d5377ebbd6227acae0d
• https://git.kernel.org/stable/c/65b655f65c3ca1ab5d598d3832bb0ff531725858
• https://git.kernel.org/stable/c/79c7c59bb519db6f5a2a151965e825ec725614cc
• https://git.kernel.org/stable/c/7c3264d273d524aa6adcce23c01087271f13586f
• https://git.kernel.org/stable/c/aaa3bb2bbf2ccbfea9e4e0b9dabf3afc60b50cd0

• Use-after-free in Linux kernel ksmbd
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0