Stack-based buffer overflow in Linux kernel - CVE-2026-74438

Vulnerability identifier: #VU142665

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74438

CWE-ID: CWE-121

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to execute arbitrary code or cause a denial of service.

The vulnerability exists due to a stack-based buffer overflow in sun4i_ss_prng_seed() in the sun4i_ss_prng rng implementation when processing a seed supplied through the AF_ALG "rng" algorithm interface. A local user can supply an oversized seed to trigger memory corruption and execute arbitrary code or cause a denial of service.

The vulnerable code path is described as only theoretically usable via the "rng" algorithm type of AF_ALG.

Linux kernel
Ubuntu
linux-nvidia (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

• https://git.kernel.org/stable/c/2eafecaba1b46bb9774eaf3556619fd5b6a17c1c
• https://git.kernel.org/stable/c/306ded31bfa00a69d25823a60d7c797170bfb4f8
• https://git.kernel.org/stable/c/9c8086d9511189c34dfa3f9e3a03f2bee12f56a5
• https://git.kernel.org/stable/c/b2c41fa9dd8fc740c489e060b199165771f268d1
• https://git.kernel.org/stable/c/c401492e01c7bfd38cf14c94d85c7efafe7d1a25
• https://git.kernel.org/stable/c/e4b7b9819811c4c51064c3d3d3c02f0be7491707
• https://git.kernel.org/stable/c/ee2458f8188732aa53a5d42f56e87bfad288b44e

• Stack-based buffer overflow in Linux kernel allwinner sun4i-ss driver
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia-tegra
• Ubuntu update for linux
• Ubuntu update for linux-azure
• Ubuntu update for linux-oem-7.0