NULL pointer dereference in Linux kernel - CVE-2026-64417
Published: July 27, 2026
Vulnerability identifier: #VU139552
CSH Severity: Low
CVSS v4: 6.8 [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]
CVE-ID: CVE-2026-64417
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in shrinker_debugfs_add() debugfs file handling when writing to a debugfs count or scan file for a shrinker with a missing callback. A local user can write to a crafted debugfs file associated with such a shrinker to cause a denial of service.
The issue can be triggered when a shrinker implements only one of the count_objects() or scan_objects() callbacks, such as the xen-backend shrinker example described in the advisory.
Affected software
Linux kernel
How to mitigate CVE-2026-64417
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/006467ab932698612398f853344a7405164541f4
- https://git.kernel.org/stable/c/09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9
- https://git.kernel.org/stable/c/36f8534f461222291a74156ab91f3ba9f09b6f93
- https://git.kernel.org/stable/c/b9beed2322f3538b0d2d53307062da4102b8d8d8
- https://git.kernel.org/stable/c/e30453c61e185e914fde83c650e268067b140218
- https://git.kernel.org/stable/c/ebb45c2648b1f60715fd283700f651e05e431231