{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7bf4796dd09984ad1612877a82d0d139c70ae27f"
            },
            {
              "fixed": "ceffe81a0be92afc0cd1340bc8ca46559cce9bb4"
            },
            {
              "fixed": "9c2d6770a5f4545a307eb66979bef7656a34d621"
            },
            {
              "fixed": "6275796f22bb382f3e9aa58ed0b4ef7bdad78cb8"
            },
            {
              "fixed": "aaac3bed034239e1d75732211d9b05f30b0b4f35"
            },
            {
              "fixed": "ad85961004fd4bd2f31209ac4b07612c6cefb9e7"
            },
            {
              "fixed": "613c8f4a501421dd258b07ea614205d4e16ec845"
            },
            {
              "fixed": "b3b7e850e1541f0520c4a12ec884255c30427ff6"
            },
            {
              "fixed": "29c95185ba32b621fbc3800fb86e7dc3edf5c2be"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.3.0"
            },
            {
              "fixed": "5.10.258"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.209"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.175"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.141"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.91"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.33"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53012.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: fix IPv6 route referencing IPv4 nexthop\n\nsyzbot reported a panic [1] [2].\n\nWhen an IPv6 nexthop is replaced with an IPv4 nexthop, the has_v4 flag\nof all groups containing this nexthop is not updated. This is because\nnh_group_v4_update is only called when replacing AF_INET to AF_INET6,\nbut the reverse direction (AF_INET6 to AF_INET) is missed.\n\nThis allows a stale has_v4=false to bypass fib6_check_nexthop, causing\nIPv6 routes to be attached to groups that effectively contain only AF_INET\nmembers. Subsequent route lookups then call nexthop_fib6_nh() which\nreturns NULL for the AF_INET member, leading to a NULL pointer\ndereference.\n\nFix by calling nh_group_v4_update whenever the family changes, not just\nAF_INET to AF_INET6.\n\nReproducer:\n\t# AF_INET6 blackhole\n\tip -6 nexthop add id 1 blackhole\n\t# group with has_v4=false\n\tip nexthop add id 100 group 1\n\t# replace with AF_INET (no -6), has_v4 stays false\n\tip nexthop replace id 1 blackhole\n\t# pass stale has_v4 check\n\tip -6 route add 2001:db8::/64 nhid 100\n\t# panic\n\tping -6 2001:db8::1\n\n[1] https://syzkaller.appspot.com/bug?id=e17283eb2f8dcf3dd9b47fe6f67a95f71faadad0\n[2] https://syzkaller.appspot.com/bug?id=8699b6ae54c9f35837d925686208402949e12ef3",
  "id": "CVE-2026-53012",
  "modified": "2026-07-16T03:31:09.887371588Z",
  "published": "2026-06-24T16:29:22.973Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/29c95185ba32b621fbc3800fb86e7dc3edf5c2be"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/613c8f4a501421dd258b07ea614205d4e16ec845"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6275796f22bb382f3e9aa58ed0b4ef7bdad78cb8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9c2d6770a5f4545a307eb66979bef7656a34d621"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aaac3bed034239e1d75732211d9b05f30b0b4f35"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad85961004fd4bd2f31209ac4b07612c6cefb9e7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b3b7e850e1541f0520c4a12ec884255c30427ff6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ceffe81a0be92afc0cd1340bc8ca46559cce9bb4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53012.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53012"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "nexthop: fix IPv6 route referencing IPv4 nexthop"
}