NULL pointer dereference in Linux kernel - CVE-2026-63986
Published: July 20, 2026
Vulnerability identifier: #VU138670
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-2026-63986
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 improper handling of an error pointer in net/ethtool/tsinfo.c when processing ethtool tsinfo dump requests. A local user can trigger the vulnerable code path to cause a denial of service.
The issue occurs because a failed prepare operation can leave no generic netlink message to cancel, leading to a kernel crash when an error pointer is passed to genlmsg_cancel().
How to mitigate CVE-2026-63986
Install security update from vendor's repository.