NULL pointer dereference in Linux kernel - CVE-2026-31577
Published: April 25, 2026
Vulnerability identifier: #VU127818
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-2026-31577
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 nilfs_mdt_save_to_shadow_map() when handling NILFS_IOCTL_CLEAN_SEGMENTS immediately after mount before any btree operation has occurred on the DAT inode. A local user can invoke the ioctl in that state to cause a denial of service.
The issue occurs because the DAT inode's i_assoc_inode may remain uninitialized until a btree operation is performed.
How to mitigate CVE-2026-31577
Install security update from vendor's repository.