Use-after-free in Linux kernel - CVE-2026-45837
Published: May 28, 2026
Vulnerability identifier: #VU132653
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-2026-45837
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 use-after-free in arena_vm_close and bpf_arena_free_pages when handling inherited arena VMAs after a fork. A local user can trigger a stale VMA reference by calling bpf_arena_free_pages() in a child process after the parent unmaps the arena to cause a denial of service.
The issue occurs when an arena VMA is inherited across fork and the child retains a pointer to the parent VMA.
How to mitigate CVE-2026-45837
Install security update from vendor's repository.