NULL Pointer Dereference in Linux kernel - CVE-2026-23249

 

NULL Pointer Dereference in Linux kernel - CVE-2026-23249

Published: March 20, 2026


Vulnerability identifier: #VU124199
CSH Severity: Low
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23249
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a null pointer dereference in the XFS filesystem's btree revalidation functionality when handling ioctl requests. A local user can trigger a specially crafted ioctl request to cause a null pointer dereference and crash the system.

The attacker must have privileges to perform XFS filesystem scrub operations, which typically requires administrative privileges.


Affected software

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux (Debian package)

How to mitigate CVE-2026-23249

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1029.30
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - update to 6.8.0-1060.64
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
linux (Debian package) - update to 6.12.85-1

External References

Related Security Bulletins