CVE-2026-45844

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: arp_tables: fix IEEE1394 ARP payload parsing

Weiming Shi says:

"arp_packet_match() unconditionally parses the ARP payload assuming two

hardware addresses are present (source and target). However,

IPv4-over-IEEE1394 ARP (RFC 2734) omits the target hardware address

field, and arp_hdr_len() already accounts for this by returning a

shorter length for ARPHRD_IEEE1394 devices.

As a result, on IEEE1394 interfaces arp_packet_match() advances past a

nonexistent target hardware address and reads the wrong bytes for both

the target device address comparison and the target IP address. This

causes arptables rules to match against garbage data, leading to

incorrect filtering decisions: packets that should be accepted may be

dropped and vice versa.

The ARP stack in net/ipv4/arp.c (arp_create and arp_process) already

handles this correctly by skipping the target hardware address for

ARPHRD_IEEE1394. Apply the same patt

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References