NULL pointer dereference in Linux kernel - CVE-2026-63972

Vulnerability identifier: #VU138674

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-2026-63972

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 mana_detach() when handling queue reset recovery after a previous detach succeeded but attach failed. A local user can trigger queue reset handling to cause a denial of service.

The issue occurs when the port is already in a detached state and transmit and receive queue resources have already been freed.

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/5b05aa36ee24297d7296ca58dfd8c448d0e4cda3
• https://git.kernel.org/stable/c/7ae590797f9b5c240aaea5773f5f00977a42a846
• https://git.kernel.org/stable/c/c4152b4e28b3e550ec99351bf900e2c24c2608cc

• NULL pointer dereference in Linux kernel microsoft mana 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