Use-after-free in Linux kernel - CVE-2026-23461

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Main Vulnerability Database Vulnerabilities #VU124906

Use-after-free in Linux kernel - CVE-2026-23461

Published: April 6, 2026


Vulnerability identifier: #VU124906
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-2026-23461
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a use-after-free in l2cap_unregister_user when accessing conn->users and conn->hchan concurrently with l2cap_conn_del(). A local attacker can trigger a race condition to cause a denial of service.

The issue is caused by inconsistent locking on the l2cap_conn structure and may also result in list corruption.


Affected software

Linux kernel
Debian Linux
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 Workstation Extension 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 Live Patching
SUSE Real Time Module
Basesystem Module
Development Tools Module
Legacy Module
Public Cloud Module
Ubuntu
openEuler
kgraft-patch-4_12_14-122_310-default
kernel-livepatch-6_4_0-150700_7_54-rt
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo
kernel-livepatch-6_4_0-150700_53_55-default
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo
cluster-md-kmp-default-debuginfo
kernel-default-base
dlm-kmp-default-debuginfo
kernel-default-devel
ocfs2-kmp-default
kernel-default-base-debuginfo
ocfs2-kmp-default-debuginfo
cluster-md-kmp-default
dlm-kmp-default
kernel-default-debugsource
gfs2-kmp-default
kernel-syms
gfs2-kmp-default-debuginfo
kernel-default-debuginfo
kernel-default
kernel-source
kernel-devel
kernel-macros
kernel-default-man
kernel-default-devel-debuginfo
kernel-default-kgraft
kernel-default-kgraft-devel
dlm-kmp-rt
kernel-rt
kernel-source-rt
kernel-devel-rt
gfs2-kmp-rt-debuginfo
cluster-md-kmp-rt
ocfs2-kmp-rt
kernel-syms-rt
gfs2-kmp-rt
kernel-rt-debugsource
cluster-md-kmp-rt-debuginfo
kernel-rt-debuginfo
kernel-rt-devel-debuginfo
dlm-kmp-rt-debuginfo
kernel-rt-devel
ocfs2-kmp-rt-debuginfo
kernel-64kb-debuginfo
kernel-obs-build
kernel-docs
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-zfcpdump
kernel-default-livepatch-devel
kernel-64kb-devel
kernel-64kb-debugsource
kernel-64kb-devel-debuginfo
kernel-64kb
kernel-default-livepatch
kernel-obs-build-debugsource
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-azure
kernel-azure-debugsource
kernel-azure-debuginfo
kernel-azure-devel-debuginfo
kernel-azure-devel
kernel-default-extra-debuginfo
kernel-default-extra
python3-perf
python3-perf-debuginfo
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-headers
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-extra-modules
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux (Debian package)

How to mitigate CVE-2026-23461

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_310-default - update to 1-8.3.1
kernel-livepatch-6_4_0-150700_7_54-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7-RT_Update_15-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_54-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_53_55-default - update to 1-150700.15.3.1
kernel-livepatch-SLE15-SP7_Update_15-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_55-default-debuginfo - update to 1-150700.15.3.1
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-base - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1.150700.17.33.1
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-base-debuginfo - update to 4.12.14-122.310.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
cluster-md-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
dlm-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-debugsource - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
gfs2-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-syms - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-source - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-macros - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-man - update to 4.12.14-122.310.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-kgraft - update to 4.12.14-122.310.1
kernel-default-kgraft-devel - update to 4.12.14-122.310.1
dlm-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-rt - update to 6.4.0-150700.7.54.1
kernel-source-rt - update to 6.4.0-150700.7.54.1
kernel-devel-rt - update to 6.4.0-150700.7.54.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-syms-rt - update to 6.4.0-150700.7.54.1
gfs2-kmp-rt - update to 6.4.0-150700.7.54.1
kernel-rt-debugsource - update to 6.4.0-150700.7.54.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.54.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel - update to 6.4.0-150700.7.54.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.55.1
kernel-obs-build - update to 6.4.0-150700.53.55.1
kernel-docs - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump - update to 6.4.0-150700.53.55.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.55.1
kernel-64kb-devel - update to 6.4.0-150700.53.55.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.55.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb - update to 6.4.0-150700.53.55.1
kernel-default-livepatch - update to 6.4.0-150700.53.55.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default - update to 6.4.0-150700.53.55.1
kernel-azure - update to 6.4.0-150700.53.55.1
kernel-azure-debugsource - update to 6.4.0-150700.53.55.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel - update to 6.4.0-150700.53.55.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.55.1
kernel-default-extra - update to 6.4.0-150700.53.55.1
python3-perf - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
python3-perf-debuginfo - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
perf-debuginfo - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
perf - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-tools-devel - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-tools-debuginfo - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-tools - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-source - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-headers - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-devel - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-debugsource - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-debuginfo - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
bpftool-debuginfo - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
bpftool - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel - addressed in versions 6.6.0-145.0.3.131, 6.6.0-145.0.3.143, 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
kernel-extra-modules - addressed in versions 6.6.0-145.0.3.144, 6.6.0-145.3.14.145
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux (Debian package) - update to 6.12.85-1

External References

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