Out-of-bounds read in Linux kernel - CVE-2026-98623

Vulnerability identifier: #VU156933

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-2026-98623

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to trigger an out-of-bounds kernel memory read, potentially causing a denial of service.

The vulnerability exists due to an out-of-bounds read in the Nouveau driver's nvkm_clk_ustate_update() function when processing a power-state identifier supplied through the pstate debugfs file. A local privileged user can request an identifier absent from clk->states, including any identifier when the list is empty, to cause the function to dereference the list head as a struct nvkm_pstate after an unsuccessful search, potentially causing 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/0d096a7f7d79207490858dde731b16da5337e90c
• https://git.kernel.org/stable/c/391517da7fd54ae40e4a7fe1cc696217343b0061
• https://git.kernel.org/stable/c/492e9cfa12f35f7946ea1b78a19f1f9337d62248
• https://git.kernel.org/stable/c/5315c7bacfe274ddfe649d9556e9a341ffa812da
• https://git.kernel.org/stable/c/9d550924961f61a491dd95359c63494fa8a23d9f
• https://git.kernel.org/stable/c/a867abcfa85ab487066c3d3008a1ba905da04113
• https://git.kernel.org/stable/c/aff09d9e37e02dc60bde79035ac15b136d602259
• https://git.kernel.org/stable/c/db5dd9f47b4df1be322f498d846e9a82940a7390

• Out-of-bounds read in Linux kernel subdev clk 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