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FKIE_CVE-2026-72256

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_cluster: reject template conntracks in hash match xt_cluster_mt() treats any non-NULL nf_ct_get() result as a fully initialized conntrack and passes it to xt_cluster_hash(). This causes a state confusion bug when the raw table CT target attaches a template conntrack to skb->_nfct before normal conntrack processing. Templates carry IPS_TEMPLATE status but do not have a valid tuple for hashing yet, so xt_cluster_hash() can hit its WARN_ON() path on the zeroed l3num field. Reject template conntracks before hashing them. This matches existing netfilter handling for template objects and avoids hashing incomplete conntrack state.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/xt_cluster.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4558bd7b47c7be82dffd837f27be8ea3ecee557d",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "d5f9d050b0b267227c1f02f11021872c7768a9cc",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "4cb8b5f586e41c187942291cc0938006077fa79e",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "fac2fdac3baad9ffd12b3b0bba4374d4b3585d54",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "13ea4f86cf738c74be2146886ac261988a631e62",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            },
            {
              "lessThan": "5feba91006ec92da57acc1cc2e34df623b98541e",
              "status": "affected",
              "version": "0269ea4937343536ec7e85649932bc8c9686ea78",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/xt_cluster.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.30"
            },
            {
              "lessThan": "2.6.30",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "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\nnetfilter: xt_cluster: reject template conntracks in hash match\n\nxt_cluster_mt() treats any non-NULL nf_ct_get() result as a fully\ninitialized conntrack and passes it to xt_cluster_hash().\n\nThis causes a state confusion bug when the raw table CT target attaches\na template conntrack to skb-\u003e_nfct before normal conntrack processing.\nTemplates carry IPS_TEMPLATE status but do not have a valid tuple for\nhashing yet, so xt_cluster_hash() can hit its WARN_ON() path on the\nzeroed l3num field.\n\nReject template conntracks before hashing them. This matches existing\nnetfilter handling for template objects and avoids hashing incomplete\nconntrack state."
    }
  ],
  "id": "CVE-2026-72256",
  "lastModified": "2026-08-17T06:18:27.903",
  "metrics": {},
  "published": "2026-08-15T06:21:53.310",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/07f9ddbf5e799c24a3a52ec9bd7b729a6f6d69d5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/13ea4f86cf738c74be2146886ac261988a631e62"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4558bd7b47c7be82dffd837f27be8ea3ecee557d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4cb8b5f586e41c187942291cc0938006077fa79e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5b2d4f0010018a7aa3495aa1dbf1b7a34011e7aa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5feba91006ec92da57acc1cc2e34df623b98541e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5f9d050b0b267227c1f02f11021872c7768a9cc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fac2fdac3baad9ffd12b3b0bba4374d4b3585d54"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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