{"apiVersion":"1.0","identifier":"CVE-2026-74657","description":"In the Linux kernel, the following vulnerability has been resolved: ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops fib_nlmsg_size() still estimates nexthop space as if every gateway is encoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an IPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA. As a result, route notifications can allocate an skb that is too small. fib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the WARN_ON() that marks such failures as a fib_nlmsg_size() bug. With panic_on_warn set, this becomes a kernel panic. Mirror the actual nexthop dump layout in fib_nlmsg_size(): account for IPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop layout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is actually present.","publishedAt":"2026-08-22T16:16:39","lastModifiedAt":"2026-08-27T13:18:36","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74657","cvssScore":null,"cvssVector":"Pending","epssProbability":0.00177,"riskScore":0,"affectedProduct":"linux","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74657","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74657","en":"https://www.redsauce.net/en/cves/CVE-2026-74657","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74657","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74657","de":"https://www.redsauce.net/de/cves/CVE-2026-74657","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74657","el":"https://www.redsauce.net/el/cves/CVE-2026-74657"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74657"}}