{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb"
            },
            {
              "fixed": "79b713ef4261a8ead96af4703f89d0b5f25532e2"
            },
            {
              "fixed": "23901aa6b8a2f294c4b774436b4691f3ff863a8f"
            },
            {
              "fixed": "b740e7ddd7ca0dbfeafca3f5e52717206cf28524"
            },
            {
              "fixed": "207b3ebacb6113acaaec0d171d5307032c690004"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "6c4a0ba674f410ab99a30a16f32dac0ebfed5cd3"
            },
            {
              "last_affected": "6dcc8ba8a6074bb79040f502dc66ad23a58a1c86"
            },
            {
              "last_affected": "74e6eb7fd27ef1ccc68041dbc66e6d80d2e4a1a0"
            },
            {
              "last_affected": "025b3326c5c409b372d0103ad30f174e55adbd1b"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.15.166"
            },
            {
              "fixed": "5.16"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.1.107"
            },
            {
              "fixed": "6.2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.6.48"
            },
            {
              "fixed": "6.7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.10.7"
            },
            {
              "fixed": "6.11"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.11.0"
            },
            {
              "fixed": "6.12.75"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.14"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45859.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation\n\nUlrich reports a regression with nfqueue:\n\nIf an application did not set the 'F_GSO' capability flag and a gso\npacket with an unconfirmed nf_conn entry is received all packets are\nnow dropped instead of queued, because the check happens after\nskb_gso_segment().  In that case, we did have exclusive ownership\nof the skb and its associated conntrack entry.  The elevated use\ncount is due to skb_clone happening via skb_gso_segment().\n\nMove the check so that its peformed vs. the aggregated packet.\n\nThen, annotate the individual segments except the first one so we\ncan do a 2nd check at reinject time.\n\nFor the normal case, where userspace does in-order reinjects, this avoids\npacket drops: first reinjected segment continues traversal and confirms\nentry, remaining segments observe the confirmed entry.\n\nWhile at it, simplify nf_ct_drop_unconfirmed(): We only care about\nunconfirmed entries with a refcnt \u003e 1, there is no need to special-case\ndying entries.\n\nThis only happens with UDP.  With TCP, the only unconfirmed packet will\nbe the TCP SYN, those aren't aggregated by GRO.\n\nNext patch adds a udpgro test case to cover this scenario.",
  "id": "CVE-2026-45859",
  "modified": "2026-07-08T05:36:19.438070525Z",
  "published": "2026-05-27T12:15:39.322Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/207b3ebacb6113acaaec0d171d5307032c690004"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/23901aa6b8a2f294c4b774436b4691f3ff863a8f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/79b713ef4261a8ead96af4703f89d0b5f25532e2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b740e7ddd7ca0dbfeafca3f5e52717206cf28524"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45859.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45859"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation"
}