A flaw in the netfilter ip6t_eui64 target allows kernel code to read an Ethernet header that may be invalid for packets that are not fragmented (par->fragoff == 0). The omission of a guard that rejects such headers lets the kernel access eth_hdr(skb) even when the MAC header is malformed, which can lead to memory corruption and kernel crashes.

All Linux kernel implementations that include the ip6t_eui64 module and have not applied the patch address this vulnerability. No specific version numbers are enumerated, so any distribution running the vulnerable kernel code is potentially affected.

The vulnerability’s CVSS score indicates critical severity. Although the EPSS score is less than 1%, the existence of the flaw means an attacker can craft and send malicious IPv6 packets that traverse the ip6t_eui64 chain, potentially causing kernel crashes or denial of service. The flaw is not yet listed in the CISA KEV catalog, suggesting no known public exploits, but the high severity and the ability to trigger it over the network make it a high risk to systems exposed to untrusted IPv6 traffic.