CVE-2026-74657

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the fib nlmsg size() function where nexthop space is incorrectly estimated by assuming every gateway is encoded as an IPv4 RTA GATEWAY attribute. Because IPv4 routes can also carry an IPv6 gateway, which fib nexthop info() dumps as RTA VIA, route notifications may allocate a socket buffer (skb) that is too small. This leads to fib dump info() failing with -EMSGSIZE and rtmsg fib() triggering a WARN ON() condition. If the panic on warn setting is enabled, this sequence results in a kernel panic.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.