A buffer overflow in the Linux kl5kusb105 USB serial driver allows an attacker to write beyond the bounds of a 64‑byte bulk‑out buffer. The driver copies payload data directly into the buffer, ignoring the header space, which results in a slab out‑of‑bounds write as confirmed by KASAN. If an attacker sends 64 or more bytes to the device, the kernel may corrupt arbitrary memory, potentially enabling a local privilege escalation or denial of service on the host system.

The flaw affects the Linux kernel’s kl5kusb105 USB serial driver, but no specific kernel version numbers are listed. Any system whose kernel includes this driver and has not yet incorporated the fix is potentially vulnerable. The vendor is Linux and the product is the Linux kernel.

The CVSS score is not provided, and EPSS data is unavailable, so the probability of exploitation cannot be quantified. The vulnerability is listed as not part of the CISA KEV catalog. It is likely exploitable only from a local machine that can influence traffic to the USB serial device; however, once triggered, the flaw can corrupt kernel memory with serious consequences. The risk level is moderate to high for affected environments where the driver is active and the device is exposed to untrusted input.