FKIE_CVE-2026-45859

Vulnerability from fkie_nvd - Published: 2026-05-27 14:16 - Updated: 2026-06-17 10:52
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation Ulrich reports a regression with nfqueue: If an application did not set the 'F_GSO' capability flag and a gso packet with an unconfirmed nf_conn entry is received all packets are now dropped instead of queued, because the check happens after skb_gso_segment(). In that case, we did have exclusive ownership of the skb and its associated conntrack entry. The elevated use count is due to skb_clone happening via skb_gso_segment(). Move the check so that its peformed vs. the aggregated packet. Then, annotate the individual segments except the first one so we can do a 2nd check at reinject time. For the normal case, where userspace does in-order reinjects, this avoids packet drops: first reinjected segment continues traversal and confirms entry, remaining segments observe the confirmed entry. While at it, simplify nf_ct_drop_unconfirmed(): We only care about unconfirmed entries with a refcnt > 1, there is no need to special-case dying entries. This only happens with UDP. With TCP, the only unconfirmed packet will be the TCP SYN, those aren't aggregated by GRO. Next patch adds a udpgro test case to cover this scenario.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/207b3ebacb6113acaaec0d171d5307032c690004
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/23901aa6b8a2f294c4b774436b4691f3ff863a8f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/79b713ef4261a8ead96af4703f89d0b5f25532e2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b740e7ddd7ca0dbfeafca3f5e52717206cf28524
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_queue.h",
            "net/netfilter/nfnetlink_queue.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "79b713ef4261a8ead96af4703f89d0b5f25532e2",
              "status": "affected",
              "version": "7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb",
              "versionType": "git"
            },
            {
              "lessThan": "23901aa6b8a2f294c4b774436b4691f3ff863a8f",
              "status": "affected",
              "version": "7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb",
              "versionType": "git"
            },
            {
              "lessThan": "b740e7ddd7ca0dbfeafca3f5e52717206cf28524",
              "status": "affected",
              "version": "7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb",
              "versionType": "git"
            },
            {
              "lessThan": "207b3ebacb6113acaaec0d171d5307032c690004",
              "status": "affected",
              "version": "7d8dc1c7be8d3509e8f5164dd5df64c8e34d7eeb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6c4a0ba674f410ab99a30a16f32dac0ebfed5cd3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6dcc8ba8a6074bb79040f502dc66ad23a58a1c86",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "74e6eb7fd27ef1ccc68041dbc66e6d80d2e4a1a0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "025b3326c5c409b372d0103ad30f174e55adbd1b",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.166",
              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
              "version": "6.1.107",
              "versionType": "semver"
            },
            {
              "lessThan": "6.7",
              "status": "affected",
              "version": "6.6.48",
              "versionType": "semver"
            },
            {
              "lessThan": "6.11",
              "status": "affected",
              "version": "6.10.7",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_queue.h",
            "net/netfilter/nfnetlink_queue.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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 \u0027F_GSO\u0027 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\u0027t aggregated by GRO.\n\nNext patch adds a udpgro test case to cover this scenario."
    }
  ],
  "id": "CVE-2026-45859",
  "lastModified": "2026-06-17T10:52:37.300",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-05-27T14:16:58.060",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/207b3ebacb6113acaaec0d171d5307032c690004"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/23901aa6b8a2f294c4b774436b4691f3ff863a8f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/79b713ef4261a8ead96af4703f89d0b5f25532e2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b740e7ddd7ca0dbfeafca3f5e52717206cf28524"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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