The f81604 CAN driver in the Linux kernel does not validate the length of interrupt USB Request Blocks. When a USB device sends an URB that is shorter than expected, the driver can mistake the incomplete data for a legitimate message. This flaw can lead the kernel to process invalid data, potentially causing a denial of service or other instability. The CVE description explicitly states that the driver now detects short URBs and avoids treating the data as valid. This attack vector is inferred from the requirement for a crafted USB interrupt message, implying local or physical access to the target machine.

All Linux kernel builds that include the unpatched f81604 driver – for example kernel 6.5, the 7.0 release‑candidate series (RC1 through RC7), and any kernel matching the CPEs listed in the advisory – remain vulnerable until the fix is applied. Systems that compile the driver into the kernel or load it as a module are affected.

This vulnerability has a moderate CVSS score of 5.5 and an EPSS score of less than 1 %, indicating a low likelihood of exploitation as of the current data. It is not listed in the CISA KEV catalog. Exploitation would require an attacker to deliver a crafted USB interrupt message to a device that uses the f81604 driver. The requirement of local or physical access is inferred from the description.