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FKIE_CVE-2026-72057

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-23 13:16
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled. Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments().
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/act_ct.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fb080b6f54835d5d4d11ce3122800e6f0f6689e6",
              "status": "affected",
              "version": "0d76daf2013ce1da20eab5e26bd81d983e1c18fb",
              "versionType": "git"
            },
            {
              "lessThan": "67d6b00a54446c008f52cf70fc0c2ad0c712f85d",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "2400c4b05d58834b994500a9eec90a37db44187c",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "5c3ae5f6c7c6de73ea9b6a75154fe4ed343e1bac",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "b3d835407846134b0d54637c0281b39bebef831d",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "f7f45ceb855d9ba1cba594fb3f383255f7013fad",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "9092e15defbe6c7bc241c306093ca9d358a578e7",
              "status": "affected",
              "version": "ec624fe740b416fb68d536b37fb8eef46f90b5c2",
              "versionType": "git"
            },
            {
              "lessThan": "5.15.217",
              "status": "affected",
              "version": "5.15.13",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/act_ct.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nnet/sched: act_ct: preserve tc_skb_cb across defragmentation\n\ntcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving\nand restoring skb-\u003ecb. The defrag helper clears IPCB/IP6CB, which aliases\nthe tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through\nact_ct therefore loses qdisc metadata such as pkt_segs and can trigger\nWARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled.\n\nSave and restore the full tc_skb_cb around nf_ct_handle_fragments(),\nmatching the pattern used by ovs_ct_handle_fragments()."
    }
  ],
  "id": "CVE-2026-72057",
  "lastModified": "2026-08-23T13:16:38.580",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 4.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:21:15.153",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2400c4b05d58834b994500a9eec90a37db44187c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c3ae5f6c7c6de73ea9b6a75154fe4ed343e1bac"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/67d6b00a54446c008f52cf70fc0c2ad0c712f85d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9092e15defbe6c7bc241c306093ca9d358a578e7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b3d835407846134b0d54637c0281b39bebef831d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f7f45ceb855d9ba1cba594fb3f383255f7013fad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fb080b6f54835d5d4d11ce3122800e6f0f6689e6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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