Use-after-free in Linux kernel - CVE-2026-53399
Published: July 21, 2026
Vulnerability identifier: #VU138859
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-53399
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a use-after-free in the nfsd layout stateid handling in fs/nfsd/nfs4layouts.c when processing layout stateid allocation failures after a setlease error. A remote user can trigger a setlease failure and subsequent IDR walker access to dereference a dangling pointer to cause a denial of service.
The issue occurs because a published stateid remains referenced in the IDR after the associated memory is freed, and a related destructor path may access uninitialized delayed work on the same failure path.
How to mitigate CVE-2026-53399
Install security update from vendor's repository.