CVE-2026-23334

Vulnerability

Overview

CVE-2026-23334 is a medium-severity vulnerability in the Linux kernel's f81604 USB CAN driver. The driver fails to properly validate the length of received interrupt URB (USB Request Block) messages. When an interrupt URB with an incorrect length is received, the driver attempts to treat the data as valid rather than detecting the short message and discarding it [1][2].

Exploitation

An attacker with physical access to a USB port could potentially craft a malicious USB device or exploit an existing device to send malformed interrupt URBs to the system. The attack requires no special privileges beyond the ability to interact with the USB subsystem, but physical proximity or the ability to connect a malicious device is necessary [3].

Impact

If exploited, this flaw could lead to memory corruption or undefined behavior in the kernel CAN subsystem. The CVSS v3 score of 5.5 (Medium) reflects the potential for denial of service or information disclosure, though proof-of-concept code has not been publicly disclosed [4].

Mitigation

The vulnerability has been patched in the Linux kernel through multiple stable commits [1][2][3][4]. Users are advised to update their kernel to a version containing these fixes. No workarounds are available beyond ensuring the USB CAN device is from a trusted source.