{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "d15662682db232da77136cd348f4c9df312ca6f9"
            },
            {
              "fixed": "0f0ca602941d0a81ae9514943ca06c55159c6385"
            },
            {
              "fixed": "5307a53599fa762c06e475ee4a375252074fd324"
            },
            {
              "fixed": "7f80ad373ce4a7af5367ff273cea0f16e91387f3"
            },
            {
              "fixed": "4a5dfbae5179f6574695012a980476254df2d295"
            },
            {
              "fixed": "a59edda6eda1252340354322d8ab318b2e9052fb"
            },
            {
              "fixed": "9b22f13524fa0de0d963bbd3002df6c28bae3395"
            },
            {
              "fixed": "4ff9548d84945d2cbf9e4c207288063a200ea397"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.2.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.152"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.104"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74657.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops\n\nfib_nlmsg_size() still estimates nexthop space as if every gateway is\nencoded as an IPv4 RTA_GATEWAY attribute. IPv4 routes can also carry an\nIPv6 gateway, which fib_nexthop_info() dumps as RTA_VIA.\n\nAs a result, route notifications can allocate an skb that is too small.\nfib_dump_info() then fails with -EMSGSIZE and rtmsg_fib() hits the\nWARN_ON() that marks such failures as a fib_nlmsg_size() bug. With\npanic_on_warn set, this becomes a kernel panic.\n\nMirror the actual nexthop dump layout in fib_nlmsg_size(): account for\nIPv6 nexthop gateways dumped as RTA_VIA, for the no-header rtnexthop\nlayout used inside RTA_MULTIPATH, and for RTA_FLOW only when it is\nactually present.",
  "id": "CVE-2026-74657",
  "modified": "2026-08-23T03:42:34.700503500Z",
  "published": "2026-08-22T15:32:31.458Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f0ca602941d0a81ae9514943ca06c55159c6385"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a5dfbae5179f6574695012a980476254df2d295"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4ff9548d84945d2cbf9e4c207288063a200ea397"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5307a53599fa762c06e475ee4a375252074fd324"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7f80ad373ce4a7af5367ff273cea0f16e91387f3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9b22f13524fa0de0d963bbd3002df6c28bae3395"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a59edda6eda1252340354322d8ab318b2e9052fb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74657.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74657"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ipv4: Fix fib_nlmsg_size() for RTA_VIA nexthops"
}