Use-after-free in Linux kernel - CVE-2026-98555

Vulnerability identifier: #VU156858

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-2026-98555

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially cause a denial of service through kernel memory corruption or memory exhaustion.

The vulnerability exists due to use-after-free, double-free, and memory leaks in the Linux kernel LLC subsystem when llc_mac_hdr_init() fails during packet handling. A local user can trigger the affected error-handling paths to potentially cause a kernel crash or exhaust kernel memory through leaked packet buffers.

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/060f827aa3dc47939ee306da715cd6700d129616
• https://git.kernel.org/stable/c/41dcae82bece9f106b4dff0ee777bba8d157c8a8
• https://git.kernel.org/stable/c/72f9dd522f8d6c5a00be9695c7bb74631eb5069e
• https://git.kernel.org/stable/c/8b855b645841b5a04e20339a22bb6d593c9b790d
• https://git.kernel.org/stable/c/b859ba18b5a1067f71db5618c6a4a70d55fa308b
• https://git.kernel.org/stable/c/cb3528ad8bb46fa6252f5d14ced7febddc18515d
• https://git.kernel.org/stable/c/d360b31f1a3666579422872aa7d1a751e20b76f9
• https://git.kernel.org/stable/c/fec0fe6838a7f45175667701fb51abb23a6ffb1e

• Use-after-free 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