Out-of-bounds read in Linux kernel - CVE-2026-98640

Vulnerability identifier: #VU156952

CSH Severity: Low

CVSS v4: 6.7 [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]

CVE-ID: CVE-2026-98640

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to cause a denial of service through a kernel page fault.

The vulnerability exists due to an out-of-bounds read in the Linux kernel amd_sfh driver's PCI probe code when accessing MMIO registers without validating that PCI BAR 2 covers the required offsets. A local privileged user can trigger probing of a device with an undersized BAR 2 to cause an access beyond the mapped region and a kernel page fault.

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/5f9e2ecb725adced013fbf5f94b9f185fad2e7d9
• https://git.kernel.org/stable/c/5ff24aa7af0bca0780fe4e6effce902065f2c0a7
• https://git.kernel.org/stable/c/65bcc5f89704efe5b9d69d4ea2c1002d90c31382
• https://git.kernel.org/stable/c/7b3747d77767f066ccf4a9e8e3a8381643ab5368
• https://git.kernel.org/stable/c/92bf2883da0306ab9d1eb794acd1058fc5088ebc
• https://git.kernel.org/stable/c/dc687489131559ee52f447592f6d039a5a013061
• https://git.kernel.org/stable/c/ee25833f037fa22d23ffdbfeebabe3579e8a0346

• Out-of-bounds read in Linux kernel hid amd-sfh-hid driver
• 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