Use-after-free in Linux kernel - CVE-2026-64108
Published: July 20, 2026
Vulnerability identifier: #VU138524
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-2026-64108
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 denial of service.
The vulnerability exists due to a use-after-free condition in the cifs deferred file close handling when processing deferred file close work during unmount. A local user can open and close a file and trigger unmount activity to cause a denial of service.
The issue can be triggered because deferred close work may run after the filesystem is being unmounted, leading to a busy dentry warning.
How to mitigate CVE-2026-64108
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/5e7d9d0805e58fa3760894e73115b7a74024fd07
- https://git.kernel.org/stable/c/bdc349a87f1fb02c18c4071858a06542bfea783d
- https://git.kernel.org/stable/c/c68337442f03953237a94577beb468ab2662a851
- https://git.kernel.org/stable/c/c7364cea52531534676b9f7dbc0a477c11f4c050
- https://git.kernel.org/stable/c/e1ffa6cf662383f95816eed1b623429d82675e75
- https://git.kernel.org/stable/c/f2deaa2f409a4598eaa10f2a93a676c0632af248