Use-after-free in Linux kernel - CVE-2026-64002
Published: July 20, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in ipv4_sysctl_exit_net() when unregistering the IPv4 sysctl table while sysctl handlers may still access sysctl_local_reserved_ports. A local user can trigger access to the freed sysctl entry to cause a denial of service.
The issue affects access to /proc/sys/net/ipv4/ip_local_reserved_ports during network namespace sysctl teardown.
Affected software
Red Hat Enterprise Linux Server - AUS
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 x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - 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
openEuler
Ubuntu
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
kernel (Red Hat package)
kernel-headers
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-rt (Red Hat package)
kernel-extra-modules
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-64002
kernel (Red Hat package) - addressed in versions 4.18.0-305.203.1.el8_4, 4.18.0-372.210.1.el8_6, 5.14.0-284.190.1.el9_2, 5.14.0-427.148.1.el9_4, 5.14.0-570.138.1.el9_6, 6.12.0-55.102.1.el10_0
kernel-headers - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
python3-perf-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
python3-perf - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
perf-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
perf - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-source - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-debugsource - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
bpftool - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-rt (Red Hat package) - update to 5.14.0-284.190.1.rt14.475.el9_2
kernel-extra-modules - update to 6.6.0-145.3.29.160
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
External References
- https://git.kernel.org/stable/c/155f90be5ee8be5b110ebc0b7da33c54c83b0208
- https://git.kernel.org/stable/c/5b23a2ff379e70b6b9ff744a972b63e1f8f4d996
- https://git.kernel.org/stable/c/6512c57c4638ddec113bf42439361ba85a12048d
- https://git.kernel.org/stable/c/87a1e0fe7776da7ab411be332b4be58ac8840d10
- https://git.kernel.org/stable/c/8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57
- https://git.kernel.org/stable/c/a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c
- https://git.kernel.org/stable/c/a7f4eefb6e1458431eef9fa20fb363320d185f76
- https://git.kernel.org/stable/c/ecf45080a4d3f4526cacb8b14060fe3b49a6913b
Related Security Bulletins
- Use-after-free in Linux kernel ipv4
- Ubuntu update for linux-ibm
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws
- openEuler 22.03 LTS SP4 update for kernel
- Ubuntu update for linux-nvidia-bos
- Ubuntu update for linux-nvidia
- Red Hat Enterprise Linux 8 update for kernel
- Red Hat Enterprise Linux 8 update for kernel
- Red Hat Enterprise Linux 9 update for kernel
- Red Hat Enterprise Linux 9 update for kernel
- Red Hat Enterprise Linux 9 update for kernel-rt
- Red Hat Enterprise Linux 9 update for kernel
- Red Hat Enterprise Linux 10 update for kernel
- openEuler 24.03 LTS SP3 update for kernel