NULL pointer dereference in Linux kernel - CVE-2026-31397
Published: April 6, 2026
Vulnerability identifier: #VU124886
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-2026-31397
CWE-ID: CWE-476
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 null pointer dereference in move_pages_huge_pmd() when handling UFFDIO_MOVE for huge zero pages. A local user can trigger the vulnerable code path to cause a denial of service.
On systems with SPARSEMEM_VMEMMAP, the flaw can instead install a PMD pointing to non-existent physical memory. The issue affects handling of huge zero page mappings in the Linux kernel memory management subsystem.
How to mitigate CVE-2026-31397
Install security update from vendor's repository.