Improper resource shutdown or release in Linux kernel - CVE-2026-23401

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Main Vulnerability Database Vulnerabilities #VU124778

Improper resource shutdown or release in Linux kernel - CVE-2026-23401

Published: April 1, 2026


Vulnerability identifier: #VU124778
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-2026-23401
CWE-ID: CWE-404
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to improper handling of SPTE updates in KVM MMU when installing emulated MMIO SPTEs. A local user can trigger a page fault after host userspace modifies guest memory mappings to switch from memslot to emulated MMIO, leading to an attempt to mark an already present SPTE as MMIO, which results in a kernel warning and potential guest crash. A local user can send a specially crafted request to cause a denial of service.

The issue arises when KVM fails to drop the existing shadow-present SPTE before installing an MMIO SPTE, resulting in inconsistent MMU state and triggering a kernel warning that can crash the guest.


Affected software

Linux kernel
Debian Linux
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Anolis OS
Red Hat Enterprise Linux for Real Time
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Ubuntu
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
kpatch-patch-4_18_0-553_125_1 (Red Hat package)
kpatch-patch-5_14_0-284_172_1 (Red Hat package)
kpatch-patch-5_14_0-427_126_1 (Red Hat package)
kpatch-patch-5_14_0-570_116_1 (Red Hat package)
kpatch-patch-4_18_0-477_130_1 (Red Hat package)
kpatch-patch-4_18_0-553_109_1 (Red Hat package)
kpatch-patch-5_14_0-284_158_1 (Red Hat package)
kpatch-patch-5_14_0-427_113_1 (Red Hat package)
kpatch-patch-5_14_0-570_94_1 (Red Hat package)
kpatch-patch-4_18_0-477_120_1 (Red Hat package)
kpatch-patch-4_18_0-553_85_1 (Red Hat package)
kpatch-patch-5_14_0-284_148_1 (Red Hat package)
kpatch-patch-5_14_0-427_100_1 (Red Hat package)
kpatch-patch-5_14_0-570_66_1 (Red Hat package)
kpatch-patch-4_18_0-477_107_1 (Red Hat package)
kpatch-patch-5_14_0-570_39_1 (Red Hat package)
kpatch-patch-4_18_0-553_72_1 (Red Hat package)
kpatch-patch-5_14_0-284_134_1 (Red Hat package)
kpatch-patch-5_14_0-427_84_1 (Red Hat package)
kpatch-patch-4_18_0-477_97_1 (Red Hat package)
kpatch-patch-4_18_0-553_53_1 (Red Hat package)
kpatch-patch-5_14_0-427_68_2 (Red Hat package)
kpatch-patch-5_14_0-284_117_1 (Red Hat package)
kpatch-patch-5_14_0-570_17_1 (Red Hat package)
kernel (Red Hat package)
kernel-rt (Red Hat package)
kernel
bpftool
kernel-doc
kernel-abi-stablelists
python3-perf
perf
kernel-tools-libs-devel
kernel-tools-libs
kernel-tools
kernel-modules-extra
kernel-headers
kernel-core
kernel-cross-headers
kernel-debug
kernel-debug-core
kernel-debug-devel
kernel-debug-modules
kernel-debug-modules-extra
kernel-devel
kernel-modules
python3-perf-debuginfo
perf-debuginfo
kernel-tools-devel
kernel-tools-debuginfo
kernel-source
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
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-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux (Debian package)
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-azure-fde-6.8 (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-23401

Install security update from vendor's repository.

kpatch-patch-4_18_0-553_125_1 (Red Hat package) - update to 1-3.el8_10
kpatch-patch-5_14_0-284_172_1 (Red Hat package) - update to 1-3.el9_2
kpatch-patch-5_14_0-427_126_1 (Red Hat package) - update to 1-3.el9_4
kpatch-patch-5_14_0-570_116_1 (Red Hat package) - update to 1-3.el9_6
kpatch-patch-4_18_0-477_130_1 (Red Hat package) - update to 1-6.el8_8
kpatch-patch-4_18_0-553_109_1 (Red Hat package) - update to 1-6.el8_10
kpatch-patch-5_14_0-284_158_1 (Red Hat package) - update to 1-6.el9_2
kpatch-patch-5_14_0-427_113_1 (Red Hat package) - update to 1-6.el9_4
kpatch-patch-5_14_0-570_94_1 (Red Hat package) - update to 1-6.el9_6
kpatch-patch-4_18_0-477_120_1 (Red Hat package) - update to 1-8.el8_8
kpatch-patch-4_18_0-553_85_1 (Red Hat package) - update to 1-8.el8_10
kpatch-patch-5_14_0-284_148_1 (Red Hat package) - update to 1-8.el9_2
kpatch-patch-5_14_0-427_100_1 (Red Hat package) - update to 1-8.el9_4
kpatch-patch-5_14_0-570_66_1 (Red Hat package) - update to 1-8.el9_6
kpatch-patch-4_18_0-477_107_1 (Red Hat package) - update to 1-9.el8_8
kpatch-patch-5_14_0-570_39_1 (Red Hat package) - update to 1-9.el9_6
kpatch-patch-4_18_0-553_72_1 (Red Hat package) - update to 1-10.el8_10
kpatch-patch-5_14_0-284_134_1 (Red Hat package) - update to 1-10.el9_2
kpatch-patch-5_14_0-427_84_1 (Red Hat package) - update to 1-10.el9_4
kpatch-patch-4_18_0-477_97_1 (Red Hat package) - update to 1-13.el8_8
kpatch-patch-4_18_0-553_53_1 (Red Hat package) - update to 1-13.el8_10
kpatch-patch-5_14_0-427_68_2 (Red Hat package) - update to 1-15.el9_4
kpatch-patch-5_14_0-284_117_1 (Red Hat package) - update to 1-16.el9_2
kpatch-patch-5_14_0-570_17_1 (Red Hat package) - update to 1-18.el9_6
kernel (Red Hat package) - addressed in versions 4.18.0-372.191.1.el8_6, 4.18.0-477.143.1.el8_8, 4.18.0-553.123.1.el8_10, 5.14.0-70.178.1.el9_0, 5.14.0-427.124.1.el9_4, 5.14.0-570.112.1.el9_6, 6.12.0-55.72.1.el10_0
kernel-rt (Red Hat package) - addressed in versions 4.18.0-553.123.1.rt7.464.el8_10, 5.14.0-70.178.1.rt21.250.el9_0, 5.14.0-284.172.1.rt14.457.el9_2
kernel - update to 4.18.0-553.123.1.0.1
bpftool - update to 4.18.0-553.123.1.0.1
kernel-doc - update to 4.18.0-553.123.1.0.1
kernel-abi-stablelists - update to 4.18.0-553.123.1.0.1
python3-perf - update to 4.18.0-553.123.1.0.1
perf - update to 4.18.0-553.123.1.0.1
kernel-tools-libs-devel - update to 4.18.0-553.123.1.0.1
kernel-tools-libs - update to 4.18.0-553.123.1.0.1
kernel-tools - update to 4.18.0-553.123.1.0.1
kernel-modules-extra - update to 4.18.0-553.123.1.0.1
kernel-headers - update to 4.18.0-553.123.1.0.1
kernel-core - update to 4.18.0-553.123.1.0.1
kernel-cross-headers - update to 4.18.0-553.123.1.0.1
kernel-debug - update to 4.18.0-553.123.1.0.1
kernel-debug-core - update to 4.18.0-553.123.1.0.1
kernel-debug-devel - update to 4.18.0-553.123.1.0.1
kernel-debug-modules - update to 4.18.0-553.123.1.0.1
kernel-debug-modules-extra - update to 4.18.0-553.123.1.0.1
kernel-devel - update to 4.18.0-553.123.1.0.1
kernel-modules - update to 4.18.0-553.123.1.0.1
kernel - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf-debuginfo - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
python3-perf - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf-debuginfo - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
perf - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-devel - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools-debuginfo - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-tools - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-source - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-headers - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-devel - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debugsource - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
kernel-debuginfo - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool-debuginfo - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
bpftool - addressed in versions 5.10.0-308.0.0.211, 6.6.0-145.0.2.130, 6.6.0-145.0.2.142, 6.6.0-145.0.2.143
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-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
kernel-extra-modules - update to 6.6.0-145.0.2.143
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-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

Related Security Bulletins