Use-after-free in Linux kernel - CVE-2026-64017

Vulnerability identifier: #VU138631

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-2026-64017

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 blk-mq cached request handling in block/blk-mq.c when submitting a bio while a cached request is peeked and the task sleeps before it is removed from the plug list. A local user can trigger request handling that hits this race condition to cause a denial of service.

The issue occurs when a plug flush frees cached requests before the cached request is popped for use.

Linux kernel
Debian Linux
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 Server - AUS
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
Ubuntu
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
kernel (Red Hat package)
linux-nvidia-tegra (Ubuntu package)
linux (Debian package)
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
IBM DataPower Gateway

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
IBM DataPower Gateway - update to 11.0.0.3
kernel (Red Hat package) - addressed in versions 5.14.0-570.142.1.el9_6, 6.12.0-55.108.1.el10_0
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux (Debian package) - update to 6.12.105-1
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1016.16
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/388468f7e7d1eab092cf2a39fdfb502e52019ec6
• https://git.kernel.org/stable/c/dc278e9bf2b9513a763353e6b9cc21e0f532954e

• Use-after-free in Linux kernel block
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia
• Debian update for linux
• Ubuntu update for linux-gcp-7.0
• Red Hat Enterprise Linux 9 update for kernel
• Multiple vulnerabilities in IBM DataPower Gateway
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure-7.0
• Red Hat Enterprise Linux 10 update for kernel
• Ubuntu update for linux-nvidia-tegra