NULL pointer dereference in Linux kernel - CVE-2026-64228
Published: July 27, 2026
Vulnerability identifier: #VU139778
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-2026-64228
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 net/ethtool/phy.c when handling ETHTOOL_MSG_PHY_GET requests for a phy_device whose PHY driver has been unbound. A local user can unbind the PHY driver via sysfs and trigger the request to cause a denial of service.
The issue occurs because the phy_device can remain attached to its net_device after the PHY driver is unbound, leaving the device reachable through the link topology xarray.
How to mitigate CVE-2026-64228
Install security update from vendor's repository.