NULL pointer dereference in Linux kernel - CVE-2026-23439
Published: April 6, 2026
Vulnerability identifier: #VU124936
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-23439
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 privileged user to cause a denial of service.
The vulnerability exists due to a null pointer dereference in udp_sock_create6() and its caller fou_create() when handling netlink requests with CONFIG_IPV6 disabled. A local privileged user can send a specially crafted netlink request to cause a denial of service.
Only privileged users can trigger the issue, and exploitation requires a kernel built with CONFIG_IPV6 disabled.
How to mitigate CVE-2026-23439
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/003343985f26dfefd0c94b1fe1316a2de74428b9
- https://git.kernel.org/stable/c/12aa4b73a67d95bc739995a2d6943aec2f9785c9
- https://git.kernel.org/stable/c/9f036aa0fe46c19e938f03d10e02c23f4fffae5e
- https://git.kernel.org/stable/c/a05a2149386f6dfb4245f522acdbef892acafc84
- https://git.kernel.org/stable/c/b3a6df291fecf5f8a308953b65ca72b7fc9e015d
- https://git.kernel.org/stable/c/ba7c9ddcdd077942b798979edb035207374d4096