Out-of-bounds write in Linux kernel - CVE-2026-53194

Vulnerability identifier: #VU135600

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53194

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to an out-of-bounds write in klsi_105_prepare_write_buffer() when processing writes to the tty device. A local user can write bulk_out_size or more bytes to the tty to cause a denial of service.

The issue is triggered when the write fifo holds at least the full bulk-out buffer size, causing data to be copied starting two bytes into a 64-byte buffer.

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 Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Live Patching
SUSE Real Time Module
Basesystem Module
Development Tools Module
Legacy Module
Public Cloud Module
openEuler
Ubuntu
kgraft-patch-4_12_14-122_320-default
kernel-livepatch-6_4_0-150700_7_67-rt
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo
kernel-livepatch-SLE15-SP7_Update_19-debugsource
kernel-livepatch-6_4_0-150700_53_73-default
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo
kernel-default-devel-debuginfo
kernel-default-devel
kernel-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-syms
ocfs2-kmp-default-debuginfo
gfs2-kmp-default
ocfs2-kmp-default
dlm-kmp-default-debuginfo
kernel-default-debuginfo
dlm-kmp-default
cluster-md-kmp-default-debuginfo
kernel-default-base-debuginfo
kernel-default-debugsource
kernel-default-base
kernel-default-kgraft-devel
kernel-default-kgraft
kernel-default-man
kernel-devel
kernel-macros
kernel-source
kernel-tools-devel
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-tools
python3-perf-debuginfo
python3-perf
python2-perf-debuginfo
python2-perf
perf-debuginfo
perf
kernel-tools-debuginfo
kernel-headers
ocfs2-kmp-rt
kernel-rt-devel-debuginfo
kernel-rt
kernel-source-rt
kernel-devel-rt
kernel-rt-debuginfo
cluster-md-kmp-rt
kernel-rt-debugsource
ocfs2-kmp-rt-debuginfo
kernel-syms-rt
cluster-md-kmp-rt-debuginfo
gfs2-kmp-rt-debuginfo
kernel-rt-devel
gfs2-kmp-rt
dlm-kmp-rt-debuginfo
dlm-kmp-rt
kernel-docs
reiserfs-kmp-default-debuginfo
kernel-default-extra-debuginfo
reiserfs-kmp-default
kernel-obs-build-debugsource
kernel-obs-build
kernel-default-extra
kernel-64kb-devel-debuginfo
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-azure
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-azure-debugsource
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-64kb-debuginfo
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-extra-modules
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_320-default - update to 1-8.3.1
kernel-livepatch-6_4_0-150700_7_67-rt - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7-RT_Update_18-debugsource - update to 1-150700.1.5.1
kernel-livepatch-6_4_0-150700_7_67-rt-debuginfo - update to 1-150700.1.5.1
kernel-livepatch-SLE15-SP7_Update_19-debugsource - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default - update to 1-150700.15.3.4
kernel-livepatch-6_4_0-150700_53_73-default-debuginfo - update to 1-150700.15.3.4
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-default-devel - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
cluster-md-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-syms - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
gfs2-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
ocfs2-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
dlm-kmp-default - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-default-base-debuginfo - update to 4.12.14-122.320.1
kernel-default-debugsource - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2
kernel-default-base - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.2.150700.17.41.4
kernel-default-kgraft-devel - update to 4.12.14-122.320.1
kernel-default-kgraft - update to 4.12.14-122.320.1
kernel-default-man - update to 4.12.14-122.320.1
kernel-devel - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.1
kernel-macros - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.1
kernel-source - addressed in versions 4.12.14-122.320.1, 6.4.0-150700.53.73.1
kernel-tools-devel - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
bpftool - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
bpftool-debuginfo - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-debuginfo - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-debugsource - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-devel - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-source - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-tools - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
python3-perf-debuginfo - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
python3-perf - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
python2-perf-debuginfo - update to 4.19.90-2607.1.0.0379
python2-perf - update to 4.19.90-2607.1.0.0379
perf-debuginfo - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
perf - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-tools-debuginfo - addressed in versions 4.19.90-2607.1.0.0379, 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
kernel-headers - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.22.159, 6.6.0-145.3.26.157
ocfs2-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt - update to 6.4.0-150700.7.67.1
kernel-source-rt - update to 6.4.0-150700.7.67.1
kernel-devel-rt - update to 6.4.0-150700.7.67.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-rt-debugsource - update to 6.4.0-150700.7.67.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-syms-rt - update to 6.4.0-150700.7.67.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
kernel-rt-devel - update to 6.4.0-150700.7.67.1
gfs2-kmp-rt - update to 6.4.0-150700.7.67.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.67.1
dlm-kmp-rt - update to 6.4.0-150700.7.67.1
kernel-docs - update to 6.4.0-150700.53.73.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.73.2
reiserfs-kmp-default - update to 6.4.0-150700.53.73.2
kernel-obs-build-debugsource - update to 6.4.0-150700.53.73.2
kernel-obs-build - update to 6.4.0-150700.53.73.2
kernel-default-extra - update to 6.4.0-150700.53.73.2
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-default-livepatch-devel - update to 6.4.0-150700.53.73.2
kernel-default-livepatch - update to 6.4.0-150700.53.73.2
kernel-azure - update to 6.4.0-150700.53.73.2
kernel-azure-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.73.2
kernel-azure-devel - update to 6.4.0-150700.53.73.2
kernel-azure-debugsource - update to 6.4.0-150700.53.73.2
kernel-64kb - update to 6.4.0-150700.53.73.2
kernel-64kb-debugsource - update to 6.4.0-150700.53.73.2
kernel-64kb-devel - update to 6.4.0-150700.53.73.2
kernel-64kb-debuginfo - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.73.2
kernel-zfcpdump - update to 6.4.0-150700.53.73.2
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.73.2
kernel-extra-modules - update to 6.6.0-145.3.26.157
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

• https://git.kernel.org/stable/c/0a57320f71941d4e0b1307453c9a1f0939afe666
• https://git.kernel.org/stable/c/14147b7963685957839c76ba8094924e22777d79
• https://git.kernel.org/stable/c/372f33ebed747d91870f57c0a2e62884a870bffa
• https://git.kernel.org/stable/c/60af1fd82983c26604102e63a3fcc822c186cceb
• https://git.kernel.org/stable/c/70d86e355c564b5510fde61361df014f5476c83e
• https://git.kernel.org/stable/c/96d47e40bf9db4a9efd5c8fb53287a508d165f14
• https://git.kernel.org/stable/c/a1288cd700f721c1a119c4f1e8efa234e59caada
• https://git.kernel.org/stable/c/bde742b076cbe26ecc89c8c68c76ae076a524d02

• Out-of-bounds write in Linux kernel usb serial driver
• openEuler 22.03 LTS SP4 update for kernel
• openEuler 20.03 LTS SP4 update for kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel
• openEuler 24.03 LTS SP3 update for kernel
• openEuler 24.03 LTS SP1 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-ibm
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia-7.0