Use-after-free in Linux kernel - CVE-2026-74746

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Main Vulnerability Database Vulnerabilities #VU145979

Use-after-free in Linux kernel - CVE-2026-74746

Published: August 27, 2026


Vulnerability identifier: #VU145979
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74746
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a use-after-free in the netfilter flowtable subsystem when inserting flow tuple nodes into the rhashtable. A remote attacker can trigger garbage collection to observe a partially installed flow to execute arbitrary code.

KASAN reported read and write access to freed slab memory in the flowtable and rhashtable path.


Affected software

Linux kernel
SUSE Linux Micro Extras
SUSE Linux Micro
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 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 x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Ubuntu
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-realtime (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-lowlatency-hwe-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-vmware (Ubuntu package)
linux-ibm-6.8 (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-azure-fde-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
kernel (Red Hat package)
kernel-rt (Red Hat package)
kernel-64kb
kernel-default-debugsource
kernel-obs-build-debugsource
kernel-obs-build
kernel-syms
kernel-default-devel
kernel-64kb-devel
kernel-64kb-debugsource
kernel-default-devel-debuginfo
kernel-default

How to mitigate CVE-2026-74746

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 5.15.0-202.212, 6.8.0-149.149, 7.0.0-42.42
linux-kvm (Ubuntu package) - update to 5.15.0-1111.116
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1120.130, 6.8.0-1073.81, 7.0.0-1016.18
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1119.126, 6.8.0-1069.74, 7.0.0-1016.17
linux-azure (Ubuntu package) - addressed in versions 5.15.0-1125.134, 6.8.0-1073.82, 7.0.0-1020.21
linux-raspi (Ubuntu package) - addressed in versions 5.15.0-1113.116, 6.8.0-1068.72, 7.0.0-1023.23
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1116.122, 6.8.0-1067.71, 7.0.0-1015.16
linux-lowlatency (Ubuntu package) - addressed in versions 5.15.0-197.207, 6.8.0-149.149.1
linux-gke (Ubuntu package) - addressed in versions 5.15.0-1115.121, 6.8.0-1068.77, 7.0.0-1010.11
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1119.126~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-197.207~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-202.212~20.04.1
linux-fips (Ubuntu package) - update to 5.15.0-202.212+fips1
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1125.134~20.04.1
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1124.133~20.04.1
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1114.120
linux-gkeop (Ubuntu package) - addressed in versions 5.15.0-1102.110, 6.8.0-1053.57
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1114.115, 6.8.0-1067.70
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1113.117~20.04.1
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1070.72, 6.8.0-1036.39
linux-realtime (Ubuntu package) - addressed in versions 5.15.0-1118.127, 6.8.1-1064.65, 7.0.0-43.43.1
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1113.117, 6.8.0-1069.70, 7.0.0-1017.17
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1116.122~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1120.130~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1111.115
linux-gcp-fips (Ubuntu package) - addressed in versions 5.15.0-1120.130+fips1, 6.8.0-1073.81+fips1
linux-aws-fips (Ubuntu package) - addressed in versions 5.15.0-1119.126+fips1, 6.8.0-1069.74+fips1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0-1125.134+fips1, 6.8.0-1073.82+fips1
linux-azure-fde (Ubuntu package) - addressed in versions 6.8.0-1071.78, 7.0.0-1019.19
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-149.149~22.04.1
linux-lowlatency-hwe-6.8 (Ubuntu package) - update to 6.8.0-149.149.1~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1071.78~22.04.1
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1073.82~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1067.71~22.04.1
linux-aws-6.8 (Ubuntu package) - update to 6.8.0-1069.74~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1067.70.1
linux-vmware (Ubuntu package) - update to 6.8.0-1010.10
linux-ibm-6.8 (Ubuntu package) - update to 6.8.0-1069.70~22.04.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1073.81~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2056.58
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1064.65~22.04.1
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-azure-fde-7.0 (Ubuntu package) - update to 7.0.0-1019.19~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1017.19~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1016.18~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1017.18~24.04.1
kernel (Red Hat package) - addressed in versions 4.18.0-305.211.1.el8_4, 4.18.0-372.220.1.el8_6, 4.18.0-477.172.1.el8_8, 4.18.0-553.171.1.el8_10, 5.14.0-427.153.1.el9_4, 5.14.0-570.146.1.el9_6, 5.14.0-687.55.1.el9_8, 6.12.0-55.108.1.el10_0
kernel-rt (Red Hat package) - addressed in versions 4.18.0-553.171.1.rt7.512.el8_10, 5.14.0-284.195.1.rt14.480.el9_2
kernel-64kb - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1
kernel-default - update to 6.4.0-159998.55.1

External References

Related Security Bulletins