CVE-2026-17523

A flaw was found in the Linux kernel in net/can/bcm.c in can: bcm, where an unprivileged local user can exploit this vulnerability to execute arbitrary code within the kernel, which leads to a local privilege escalation (LPE). This allows the attacker to gain root privileges and take full control of the affected system.

This is an Important flaw in the Linux kernel's CAN BCM module that allows a local unprivileged attacker to achieve root privileges through arbitrary kernel code execution. The vulnerability was originally discovered in 2019 and is present in Red Hat Enterprise Linux 8, where a proof of concept has demonstrated local privilege escalation, even without unprivileged user namespaces or the kernel-modules-extra package.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, prevent the bcm kernel module from loading if it is not required. Create a file named /etc/modprobe.d/blacklist-bcm.conf with the content blacklist bcm. A system reboot is required for this change to take effect. This mitigation may impact functionality that relies on the CAN BCM module.