Improper initialization in Linux kernel - CVE-2026-98240

Vulnerability identifier: #VU153785

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-2026-98240

CWE-ID: CWE-665

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 improper initialization of the options_len counter in net/ipv4/ip_tunnel_core.c when parsing IP tunnel options during route configuration. A local user can configure an IP route with Geneve options to trigger a kernel panic and cause a denial of service.

The demonstrated panic occurs on kernels built with GCC 15 or later and CONFIG_FORTIFY_SOURCE enabled. The fortified memcpy detects a four-byte write to a destination whose reported size is zero.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/0f6a6beb01c068fcd5274eabf22c260039749fea
• https://git.kernel.org/stable/c/455ebeadf714f51e1dbbd6a022c74c9215b1cd76
• https://git.kernel.org/stable/c/9907325257b4b382f26aafd5d9a8d47915907dd5

• Improper initialization in Linux kernel ipv4
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more