Improper update of reference count in Linux kernel - CVE-2026-74735

Vulnerability identifier: #VU145993

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74735

CWE-ID: CWE-911

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 improper reference counting in the l2tp seq_file handlers for /proc/net/pppol2tp and /sys/kernel/debug/l2tp/tunnels when closing the file before reading to end-of-file. A local user can close the file early to cause a denial of service.

The issue occurs because tunnel and session references kept in seq_file private iteration state are not dropped on release.

Linux kernel
Debian Linux
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Real Time Module
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo
kernel-livepatch-6_4_0-150700_7_78-rt
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo
kernel-livepatch-SLE15-SP7_Update_22-debugsource
kernel-livepatch-6_4_0-150700_53_84-default
kernel-rt
ocfs2-kmp-rt-debuginfo
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-rt-devel
kernel-syms-rt
kernel-rt-debugsource
cluster-md-kmp-rt
dlm-kmp-rt-debuginfo
gfs2-kmp-rt
gfs2-kmp-rt-debuginfo
ocfs2-kmp-rt
dlm-kmp-rt
kernel-devel-rt
kernel-source-rt
kernel-default-livepatch-devel
kernel-default-livepatch
reiserfs-kmp-default-debuginfo
kernel-azure
kernel-azure-debugsource
kernel-azure-devel
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-default-extra
kernel-default-extra-debuginfo
kernel-macros
cluster-md-kmp-default-debuginfo
ocfs2-kmp-default
gfs2-kmp-default
dlm-kmp-default
gfs2-kmp-default-debuginfo
cluster-md-kmp-default
kernel-default-debugsource
dlm-kmp-default-debuginfo
kernel-default-debuginfo
ocfs2-kmp-default-debuginfo
kernel-default
kernel-default-devel
kernel-default-devel-debuginfo
kernel-devel
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-64kb
kernel-64kb-debuginfo
kernel-64kb-devel-debuginfo
kernel-64kb-debugsource
kernel-64kb-devel
kernel-docs
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-source
reiserfs-kmp-default
kernel-default-base
linux (Debian package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-livepatch-6_4_0-150700_7_78-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_78-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_21-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_84-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_22-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_84-default - update to 1-150700.15.3.1
kernel-rt - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.78.1
kernel-rt-devel - update to 6.4.0-150700.7.78.1
kernel-syms-rt - update to 6.4.0-150700.7.78.1
kernel-rt-debugsource - update to 6.4.0-150700.7.78.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt - update to 6.4.0-150700.7.78.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.78.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.78.1
dlm-kmp-rt - update to 6.4.0-150700.7.78.1
kernel-devel-rt - update to 6.4.0-150700.7.78.1
kernel-source-rt - update to 6.4.0-150700.7.78.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.84.1
kernel-default-livepatch - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure - update to 6.4.0-150700.53.84.1
kernel-azure-debugsource - update to 6.4.0-150700.53.84.1
kernel-azure-devel - update to 6.4.0-150700.53.84.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.84.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-extra - update to 6.4.0-150700.53.84.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.84.1
kernel-macros - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default - update to 6.4.0-150700.53.84.1
dlm-kmp-default - update to 6.4.0-150700.53.84.1
gfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
cluster-md-kmp-default - update to 6.4.0-150700.53.84.1
kernel-default-debugsource - update to 6.4.0-150700.53.84.1
dlm-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default-debuginfo - update to 6.4.0-150700.53.84.1
ocfs2-kmp-default-debuginfo - update to 6.4.0-150700.53.84.1
kernel-default - update to 6.4.0-150700.53.84.1
kernel-default-devel - update to 6.4.0-150700.53.84.1
kernel-default-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-devel - update to 6.4.0-150700.53.84.1
kernel-zfcpdump - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.84.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb - update to 6.4.0-150700.53.84.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.84.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.84.1
kernel-64kb-devel - update to 6.4.0-150700.53.84.1
kernel-docs - update to 6.4.0-150700.53.84.1
kernel-syms - update to 6.4.0-150700.53.84.1
kernel-obs-build - update to 6.4.0-150700.53.84.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.84.1
kernel-source - update to 6.4.0-150700.53.84.1
reiserfs-kmp-default - update to 6.4.0-150700.53.84.1
kernel-default-base - update to 6.4.0-150700.53.84.1.150700.17.47.1
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/9006c116dd111d457bf5d074990210f70a4ad2c8
• https://git.kernel.org/stable/c/ebe2774e956482dd3c70b8991f6f7654356339e6

• Improper update of reference count in Linux kernel l2tp
• Debian update for linux
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel