Race condition in Linux kernel - CVE-2026-74262

Vulnerability identifier: #VU142930

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74262

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a race condition in kcm_attach() and kcm_unattach() callback handling in net/kcm/kcmsock.c when changing lower socket callbacks concurrently. A local user can trigger concurrent callback updates and execution to cause a denial of service.

The issue can lead to stale or misdirected wakeups when callback and sk_user_data state become mismatched across CPUs.

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/0cb3e2f40679032c1aa2186280a86e5ead0161ee
• https://git.kernel.org/stable/c/11faefd11ce2448bac7279ab302dd1954a6547fe
• https://git.kernel.org/stable/c/47186409c092cd7dd70350999186c700233e854d
• https://git.kernel.org/stable/c/9684fff87124b201e11dea01ded9173025359a0f
• https://git.kernel.org/stable/c/b4ccd6eef671d7c44a30123cd29f3acf3de8468e
• https://git.kernel.org/stable/c/b8c90823cdfb5f3d22f261aeb3e9066612853c36
• https://git.kernel.org/stable/c/f01fb6138f8eb606b56ce9158e2d8b72352c53f4
• https://git.kernel.org/stable/c/fa26e4606aed0f7fe793c325506adeda1d847a43

• Race condition in Linux kernel kcm
• 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