Improper synchronization in Linux kernel - CVE-2026-89986

Vulnerability identifier: #VU150304

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-2026-89986

CWE-ID: CWE-662

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to compromise confidentiality, integrity, and availability.

The vulnerability exists due to improper synchronization in alloc_pages_bulk_weighted_interleave() when allocating temporary node weights under an RCU read-side critical section. A local user can trigger the vulnerable allocation while using an MPOL_WEIGHTED_INTERLEAVE memory policy to compromise confidentiality, integrity, and availability.

Linux kernel
Debian Linux
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)
linux (Debian 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
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/0ceda28f371df9e0bbdaa29214f71fe8298f23d8
• https://git.kernel.org/stable/c/2943f1f4b7f2816177060eb9f551f2e6d8b629ba
• https://git.kernel.org/stable/c/540e583b66d6402bf556fde5e53c817a54c1afe5
• https://git.kernel.org/stable/c/bcb3d0c867ee40dc48e9c085bf328fbc679b6656

• Improper synchronization in Linux kernel mm
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more