Use After Free in Linux kernel - CVE-2026-23340

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Main Vulnerability Database Vulnerabilities #VU124511

Use After Free in Linux kernel - CVE-2026-23340

Published: March 25, 2026


Vulnerability identifier: #VU124511
CSH Severity: Low
CVSS v4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23340
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to execute arbitrary code or cause a denial of service.

The vulnerability exists due to a use-after-free in the network scheduler (qdisc) component when resetting transmit queues for lockless qdiscs during changes in the number of real transmit queues. A local user can trigger a race condition between qdisc_reset() and the packet dequeue path, leading to use-after-free and potential execution of arbitrary code or system crash.

Exploitation requires the ability to modify network interface queue configurations, which typically requires local user privileges. The issue affects systems using lockless qdiscs such as pfifo_fast, especially under high network load and frequent queue resizing operations.


Affected software

Linux kernel
Debian Linux
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise Live Patching
Development Tools Module
Public Cloud Module
Legacy Module
Basesystem Module
SUSE Real Time Module
openEuler
Ubuntu
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-debuginfo
kernel-livepatch-6_4_0-150700_53_55-default
kernel-livepatch-SLE15-SP7_Update_15-debugsource
kernel-devel
kernel-default-kgraft-devel
kernel-default-kgraft
kernel-default-devel-debuginfo
kernel-default-man
kernel-macros
kernel-source
kernel-default
gfs2-kmp-default-debuginfo
kernel-default-base
kernel-default-debugsource
dlm-kmp-default
cluster-md-kmp-default
ocfs2-kmp-default-debuginfo
kernel-default-base-debuginfo
ocfs2-kmp-default
kernel-default-devel
dlm-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
kernel-syms
gfs2-kmp-default
kernel-default-debuginfo
python3-perf-debuginfo
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python2-perf
python2-perf-debuginfo
python3-perf
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux (Debian package)
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
ocfs2-kmp-rt-debuginfo
kernel-rt-devel
kernel-64kb-debugsource
kernel-azure-devel-debuginfo
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure
kernel-64kb
reiserfs-kmp-default
reiserfs-kmp-default-debuginfo
kernel-64kb-devel
kernel-docs
kernel-64kb-devel-debuginfo
kernel-64kb-debuginfo
kernel-zfcpdump
kernel-zfcpdump-debuginfo
kernel-zfcpdump-debugsource
kernel-obs-build-debugsource
kernel-obs-build
kernel-default-extra-debuginfo
kernel-azure-devel
kernel-default-livepatch-devel
kernel-default-livepatch
kernel-default-extra
kernel-headers
kernel-extra-modules
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-raspi (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-23340

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-debuginfo - update to 1-150700.15.3.1
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-devel - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
kernel-default-kgraft-devel - update to 4.12.14-122.310.1
kernel-default-kgraft - 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-man - update to 4.12.14-122.310.1
kernel-macros - 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-default - 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-base - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1.150700.17.33.1
kernel-default-debugsource - 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
cluster-md-kmp-default - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
ocfs2-kmp-default-debuginfo - 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 - 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
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.310.1, 6.4.0-150700.53.55.1
cluster-md-kmp-default-debuginfo - 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 - 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
python3-perf-debuginfo - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
bpftool - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
bpftool-debuginfo - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-debuginfo - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-debugsource - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-devel - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools-debuginfo - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-tools-devel - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
perf - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
perf-debuginfo - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
python2-perf - update to 4.19.90-2608.6.0.0388
kernel-source - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
python2-perf-debuginfo - update to 4.19.90-2608.6.0.0388
python3-perf - addressed in versions 4.19.90-2608.6.0.0388, 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
linux (Ubuntu package) - addressed in versions 5.15.0.184.155, 5.15.0-184.194, 5.15.0-184.194~20.04.1, 5.15.0.186.166, 5.15.0-186.196, 5.15.0-186.196~20.04.1, 5.15.0.1075.78, 5.15.0-1075.79, 5.15.0.1095.94, 5.15.0-1095.103, 5.15.0.1104.100, 5.15.0-1104.109, 5.15.0.1108.107, 5.15.0-1108.114, 5.15.0.1111.115, 5.15.0-1111.120+fips1, 5.15.0.1112.102, 5.15.0.1112.109, 5.15.0-1112.122, 5.15.0-1112.122+fips1, 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-aws (Ubuntu package) - addressed in versions 5.15.0.186.109, 5.15.0-186.196+fips1, 5.15.0.1106.103, 5.15.0-1106.110, 5.15.0.1107.107, 5.15.0-1107.108, 5.15.0.1112.108, 5.15.0.1112.115, 5.15.0-1112.119, 5.15.0-1112.119+fips1, 5.15.0-1112.119~20.04.1, 6.8.0-1061.64+1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1053.53, 5.15.0.1053.55, 5.15.0.1064.64, 5.15.0-1064.66
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1064.66~20.04.1
linux-intel-iot-realtime (Ubuntu package) - addressed in versions 5.15.0-1104.106, 5.15.0.1104.108, 5.15.0-1107.113~20.04.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1106.110~20.04.1
linux-intel-iotg (Ubuntu package) - addressed in versions 5.15.0.1107.106, 5.15.0-1107.113
linux-azure (Ubuntu package) - addressed in versions 5.15.0.1109.105, 5.15.0-1109.115, 5.15.0.1117.115, 5.15.0-1117.126, 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-5.15 (Ubuntu package) - addressed in versions 5.15.0-1109.115~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1112.122~20.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0.1117.102, 5.15.0-1117.126+fips1, 6.8.0-1063.71+fips2
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1117.126, 6.8.0-1062.69
linux (Debian package) - addressed in versions 6.1.170-1, 6.12.85-1
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
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.54.1
kernel-rt-devel - update to 6.4.0-150700.7.54.1
kernel-64kb-debugsource - update to 6.4.0-150700.53.55.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-debugsource - update to 6.4.0-150700.53.55.1
kernel-azure - update to 6.4.0-150700.53.55.1
kernel-64kb - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default - update to 6.4.0-150700.53.55.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-devel - update to 6.4.0-150700.53.55.1
kernel-docs - update to 6.4.0-150700.53.55.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.55.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.55.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.55.1
kernel-obs-build-debugsource - update to 6.4.0-150700.53.55.1
kernel-obs-build - update to 6.4.0-150700.53.55.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.55.1
kernel-azure-devel - update to 6.4.0-150700.53.55.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.55.1
kernel-default-livepatch - update to 6.4.0-150700.53.55.1
kernel-default-extra - update to 6.4.0-150700.53.55.1
kernel-headers - addressed in versions 6.6.0-145.1.14.152, 6.6.0-145.3.14.145
kernel-extra-modules - update to 6.6.0-145.3.14.145
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-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

External References

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