Use-after-free in Linux kernel - CVE-2026-98840

Vulnerability identifier: #VU157208

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98840

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially cause a denial of service through a kernel use-after-free.

The vulnerability exists due to use-after-free in the Linux kernel's vcs_write() function when a copy failure exits the write loop without refreshing a virtual console pointer following concurrent console deallocation. A local user can perform virtual console writes that encounter a copy failure while racing with console deallocation to trigger a stale-pointer dereference in vcs_notifier() and potentially crash the kernel.

Linux kernel
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Live Patching
kgraft-patch-4_12_14-122_339-default
kernel-default-man
kernel-default
kernel-devel
kernel-macros
kernel-source
kernel-default-devel-debuginfo
cluster-md-kmp-default
gfs2-kmp-default
ocfs2-kmp-default
gfs2-kmp-default-debuginfo
kernel-default-base
kernel-default-base-debuginfo
dlm-kmp-default
kernel-default-devel
dlm-kmp-default-debuginfo
kernel-syms
ocfs2-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
kernel-default-kgraft-devel
kernel-default-kgraft
kernel-default-debugsource
kernel-default-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_339-default - update to 1-8.3.1
kernel-default-man - update to 4.12.14-122.339.1
kernel-default - update to 4.12.14-122.339.1
kernel-devel - update to 4.12.14-122.339.1
kernel-macros - update to 4.12.14-122.339.1
kernel-source - update to 4.12.14-122.339.1
kernel-default-devel-debuginfo - update to 4.12.14-122.339.1
cluster-md-kmp-default - update to 4.12.14-122.339.1
gfs2-kmp-default - update to 4.12.14-122.339.1
ocfs2-kmp-default - update to 4.12.14-122.339.1
gfs2-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-default-base - update to 4.12.14-122.339.1
kernel-default-base-debuginfo - update to 4.12.14-122.339.1
dlm-kmp-default - update to 4.12.14-122.339.1
kernel-default-devel - update to 4.12.14-122.339.1
dlm-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-syms - update to 4.12.14-122.339.1
ocfs2-kmp-default-debuginfo - update to 4.12.14-122.339.1
cluster-md-kmp-default-debuginfo - update to 4.12.14-122.339.1
kernel-default-kgraft-devel - update to 4.12.14-122.339.1
kernel-default-kgraft - update to 4.12.14-122.339.1
kernel-default-debugsource - update to 4.12.14-122.339.1
kernel-default-debuginfo - update to 4.12.14-122.339.1

• https://git.kernel.org/stable/c/1485a3dd97ab1af2605243cabe6b604546d46dd1
• https://git.kernel.org/stable/c/226bd5603371cd9f6642cbb9e9a677f445de3530
• https://git.kernel.org/stable/c/233a2e190b12884d186027d0b86d43a48799b69c
• https://git.kernel.org/stable/c/9dfcadc5e003fb250dd471db90144bd5366140e9
• https://git.kernel.org/stable/c/c073d01f6f5367c3a4f07efd507274ed0d03acd0

• Use-after-free in Linux kernel tty vt driver
• SUSE update for the Linux Kernel