{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449"
            },
            {
              "fixed": "a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce"
            },
            {
              "fixed": "f1281d4b99089fbaf0d3579bba62a814ebb4de4d"
            },
            {
              "fixed": "e36ce6e78fe3fc3c071a26750783b7ba081ce10d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.7.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89564.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nip: orphan prefetched skbs before multicast forwarding\n\nIPv4 and IPv6 input preserve an skb-\u003esk association installed by\nbpf_sk_assign() so that local delivery can use the selected socket under\nRCU. Both address families can also prefetch a socket in UDP early demux.\nIn both paths (BPF and UDP early demux) a reference is not guaranteed to\nbe held on the socket.\n\nWhen a multicast packet is not locally deliverable, IPv6 hands the\noriginal skb to ip6_mr_input(). IPv4's ip_mr_input() similarly keeps the\noriginal skb when local delivery is not needed. Either path can put the\nskb on an unresolved multicast route queue or forward it after the\nreceive-side RCU section ends.\n\nAfter the prefetched socket is destroyed, a later skb free invokes\nsock_pfree() and dereferences the stale skb-\u003esk. Orphan the skb before\neach non-local multicast forwarding path. Local delivery retains the\noriginal skb; the existing skb_clone() calls provide multicast forwarding\nwith a socket-free clone.",
  "id": "CVE-2026-89564",
  "modified": "2026-09-15T03:30:45.837137651Z",
  "published": "2026-09-11T19:44:35.131Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e36ce6e78fe3fc3c071a26750783b7ba081ce10d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f1281d4b99089fbaf0d3579bba62a814ebb4de4d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89564.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89564"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ip: orphan prefetched skbs before multicast forwarding"
}