Use of Uninitialized Variable in Linux kernel - CVE-2026-63936

Vulnerability identifier: #VU138706

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-63936

CWE-ID: CWE-457

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to use of uninitialized memory in mt6358_read_imp() in the mt6359 auxadc driver when handling a failed regmap read during impedance measurement. A local user can trigger the affected measurement path to disclose sensitive information.

Stack memory contents may be reported as a measurement result if the bus read fails.

Linux kernel
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/6258bfec51e894ea97b8e69f3cde7af269b37de9
• https://git.kernel.org/stable/c/944082fdb0284a31c0b37a88c8a1d4404da3a6d9
• https://git.kernel.org/stable/c/a72f8e51d6ee66c255a8a93a4421b8a538d112a8
• https://git.kernel.org/stable/c/f9bbd943c34a9ad60e593a4b99ce2394e4e2381b

• Use of Uninitialized Variable in Linux kernel iio adc driver
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia