A race condition in the batman-adv module can cause a MAC address to be partially updated while another process reads it. The reader may see an incomplete MAC address and transmit it over the network or include it in an ARP response, which enables an attacker to poison the ARP cache of neighboring devices. This flaw can lead to Man‑in‑the‑Middle attacks, packet loss, or denial of service. The weakness is a classic race condition that allows inconsistent state usage.

The vulnerability affects Linux kernels that include the batman-adv networking stack. It is present in versions that have not yet applied the patch that atomically updates MAC addresses using atomic64_t. The exact kernel releases are those prior to the commit referenced in the source list.

The EPSS score is reported as <1%, indicating a low probability of widespread exploitation, and the vulnerability is not listed in the CISA KEV catalog. Nonetheless, the attack does not require special privileges and could be triggered by a local or remote user on the same bridged network segment. The CVSS score is not provided, but based on the potential impact, the severity can be considered high. Exploitability would involve an attacker controlling network traffic to the vulnerable node, possibly in a multi‑tenant or shared‑snetwork environment. The attack vector is inferred from the race condition during MAC address updates.