Use-after-free in Linux kernel - CVE-2026-64239
Published: July 27, 2026
Vulnerability identifier: #VU139745
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-64239
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a use-after-free.
The vulnerability exists due to use-after-free in DAMON sysfs tried region directory handling when refreshing scheme tried region directories. A local user can repeatedly request directory refresh operations to cause a use-after-free.
The issue can be reproduced on kernels built with CONFIG_DEBUG_KOBJECT_RELEASE because delayed kobject release callbacks can leave freed region objects referenced from the linked list during directory regeneration.
How to mitigate CVE-2026-64239
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0ba6c05156d9ff9fc6ca22b7690e2eec9eca66f7
- https://git.kernel.org/stable/c/2c33177023c92e76806c535ddbffaa3d3fc37777
- https://git.kernel.org/stable/c/441f92f7d386b85bad16de49db95a307cba048a2
- https://git.kernel.org/stable/c/a5fa42214de55e43d165144727ce9facb9fc6b08
- https://git.kernel.org/stable/c/c0e37017a452addec873865c94cf7a665663a9b2