Use-after-free in Linux kernel - CVE-2026-68201

Vulnerability identifier: #VU142112

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-2026-68201

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 use-after-free in the ALSA timer subsystem, specifically slave timer callback handling in snd_timer_close_locked() and remove_slave_links(), when closing a master timer instance while a slave callback is still in flight. A local user can trigger timer close operations while a slave callback is active to cause a denial of service.

The issue occurs because a slave instance can be freed after its ->timer pointer is cleared, causing its close path to skip draining an already running callback.

Linux kernel
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
kernel (Red Hat package)
kernel-zfcpdump-devel (Red Hat package)
kernel-64k-devel-matched (Red Hat package)
kernel-64k-devel (Red Hat package)
kernel-64k-debug-devel-matched (Red Hat package)
kernel-64k-debug-devel (Red Hat package)
kernel-zfcpdump-devel-matched (Red Hat package)
python3-perf (Red Hat package)
perf (Red Hat package)
kernel-headers (Red Hat package)
kernel-devel-matched (Red Hat package)
kernel-devel (Red Hat package)
kernel-debug-devel-matched (Red Hat package)
kernel-debug-devel (Red Hat package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-38.38
linux-realtime (Ubuntu package) - update to 7.0.0-38.38.1
linux-aws (Ubuntu package) - update to 7.0.0-1014.14
linux-gcp (Ubuntu package) - update to 7.0.0-1014.14
linux-oracle (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1015.15
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2022.23
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-38.38~24.04.4
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1013.13~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-gke (Ubuntu package) - update to 7.0.0-1008.9
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1024.25~24.04.1
kernel (Red Hat package) - update to 5.14.0-687.51.1.el9_8
kernel-zfcpdump-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-zfcpdump-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
python3-perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-headers (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• https://git.kernel.org/stable/c/2b298997786876b225cff2446e11a0fa6f602f6d
• https://git.kernel.org/stable/c/426c0ff1c433d6030610ad4f9375746dfe931caa
• https://git.kernel.org/stable/c/bdefe1346a8e6b8dc8593406dc2617e985fcbcab
• https://git.kernel.org/stable/c/cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0

• Use-after-free in Linux kernel core
• Red Hat Enterprise Linux 9 update for kernel
• Red Hat Enterprise Linux 10 update for kernel
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux-aws-7.0
• Ubuntu update for linux-nvidia-7.0, linux-nvidia-bos