Use of Uninitialized Variable in Linux kernel - CVE-2026-80927

Vulnerability identifier: #VU149465

CSH Severity: Low

CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-80927

CWE-ID: CWE-457

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose uninitialized stack data to userspace.

The vulnerability exists due to use of an uninitialized variable in __do_adjtimex() when the auxiliary clock is disabled during tk_get_aux_ts64() and enabled before clock validity is checked. A local user can invoke adjtimex during this race to disclose uninitialized stack data to userspace.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (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 (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
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/4b61084b11bcecce86d03804ff30f8d7b465593c
• https://git.kernel.org/stable/c/bc59dac50cb45a725f7a50760c7cc72a0964f722
• https://git.kernel.org/stable/c/fecf1e37775269ad38c172b468ad4ecc3968aa63

• Use of Uninitialized Variable in Linux kernel time
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more