The bug lies in the ethtool coalesce configuration path of the Linux kernel. During a profile update, the kernel walks a Netlink nested attribute list that can contain an arbitrarily large number of entries controlled by the caller. The code writes into a five‑element array without bounding the index, resulting in an out‑of‑bounds write into the kernel heap. This memory corruption can corrupt arbitrary kernel data structures and may lead to a kernel crash or loss of integrity.

All in‑tree Linux kernel versions that include the ethtool coalesce code are affected until the upstream patch is applied. The vulnerability is documented for the Linux kernel and applies to any distribution that ships the unpatched kernel image.

The CVSS base score of 7.8 indicates a high‑impact flaw. The EPSS score of less than 1 % indicates exploitation in the wild is presently unlikely. The vulnerability requires an attacker to craft a Netlink message containing more than five nested entries and send it to the kernel. Exploitation therefore depends on the ability to send such Netlink messages and can potentially crash the system or corrupt kernel memory.