Incorrect Calculation of Buffer Size in Linux kernel - CVE-2026-98526

Vulnerability identifier: #VU156828

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98526

CWE-ID: CWE-131

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker on the local network to potentially cause a denial of service by triggering a kernel socket-buffer headroom underflow.

The vulnerability exists due to insufficient link-layer headroom allocation in llc_alloc_frame() when allocating LLC response frames for stacked Ethernet devices such as VLAN devices. A remote attacker on the local network can send LLC traffic that elicits a response through an affected device to trigger a headroom underflow in eth_header() and potentially cause a denial of service.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (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-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
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/018020f5a48cc86fdd6dc2d380f6c70443ae7639
• https://git.kernel.org/stable/c/16ceac2daa89dd16917bc488ab05b9dd6961a603
• https://git.kernel.org/stable/c/1937222c2511ac91377d39f28106c34734f5f8c6
• https://git.kernel.org/stable/c/3361c93e417384ebf28003e0fb6d5304653d3b05
• https://git.kernel.org/stable/c/3a3f57c4061d9e9cc3bc04205d36ce41ae3406c1
• https://git.kernel.org/stable/c/72b5b9a28b996e09b8b5b944370c79851bb68f52
• https://git.kernel.org/stable/c/7c38524b2b2456bd33cb360420da6cbf9cad1b33
• https://git.kernel.org/stable/c/e06f8b6e27cc616d3c587e9784c4a033eb310a16

• Incorrect Calculation of Buffer Size in Linux kernel llc
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more