NULL pointer dereference in Linux kernel - CVE-2026-64457

Vulnerability identifier: #VU139488

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64457

CWE-ID: CWE-476

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 NULL pointer dereference in virtio_pci queue handling in vp_del_vqs() when unbinding a virtio balloon device with conditional queue entries absent. A local user can write to the virtio_balloon unbind sysfs interface to cause a denial of service.

The issue occurs when optional stats, free_page, or reporting queues are not present, creating holes in the queue info array and causing a mismatch between sparse and dense queue indexing.

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

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1

• https://git.kernel.org/stable/c/075bc3c779e1ea7294afabdcb7e0a49536959b28
• https://git.kernel.org/stable/c/41e6dc1a10036c9f47057033f19af7e52ec464b6
• https://git.kernel.org/stable/c/64a4c0befa77bcc01076aec9f93863ffd4ed06b7
• https://git.kernel.org/stable/c/f7d380fb525c13bdd114369a1979c80c346e6abc

• NULL pointer dereference in Linux kernel virtio driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0