NULL pointer dereference in Linux kernel - CVE-2026-72248

Vulnerability identifier: #VU143187

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-2026-72248

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to invalid dst usage in the Linux kernel netfilter flowtable tunnel transmit path when handling direct xmit flows over IPIP tunnels. A local user can trigger crafted flow handling to cause a denial of service.

The issue occurs with the combination of IPIP tunnel support and direct xmit, such as through a bridge device.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gke (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gke (Ubuntu package) - update to 7.0.0-1007.8
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1012.12~24.04.1
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14

• https://git.kernel.org/stable/c/0880c4ed122d0cddc9f29a2b28f055d1f24f0fca
• https://git.kernel.org/stable/c/fa7395c02d95e51bad2952325d2d6503bfbad437

• NULL pointer dereference in Linux kernel netfilter
• Ubuntu update for linux-gcp
• Ubuntu update for linux
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-gke