Use-after-free in Linux kernel - CVE-2026-64073

Vulnerability identifier: #VU138573

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64073

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to a use-after-free in irq_work_single() when synchronizing irq_work on PREEMPT_RT systems. A local user can trigger concurrent irq_work activity and free the work structure after BUSY is cleared to cause a denial of service.

The issue affects non-HARD irq_work processed by per-CPU kthreads on PREEMPT_RT.

Linux kernel
openEuler
Ubuntu
kernel-debugsource
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-devel
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-extra-modules
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-debugsource - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
python3-perf-debuginfo - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
python3-perf - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
perf-debuginfo - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
perf - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-source - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-headers - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
bpftool - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel - addressed in versions 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
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

• https://git.kernel.org/stable/c/18c0456ea2615b1a743a6db739c74411c3b42bc6
• https://git.kernel.org/stable/c/2dc79362302922cb18f35e262712b5e58de65442
• https://git.kernel.org/stable/c/684a78183c54c23e70d1cba320f7fc184604210b
• https://git.kernel.org/stable/c/81b582784518196eff1050212a046bc29d3a05dd
• https://git.kernel.org/stable/c/91840be8f710370607f949a627e070896faeddb8
• https://git.kernel.org/stable/c/eef4f71b46a9929ac33e968538c9dd5d96a02460

• Use-after-free in Linux kernel irq_work_single()
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• openEuler 24.03 LTS SP1 update for kernel
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia
• openEuler 24.03 LTS SP3 update for kernel