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  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72418.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conncount: prevent connlimit drops for early confirmed ct\n\nCommit 69894e5b4c5e (\"netfilter: nft_connlimit: update the count if add\nwas skipped\") introduced a regression where packets for valid\nconnections are dropped when using connlimit for soft-limiting\nscenarios.\n\nThe issue occurs when a new connection reuses a socket currently in\nthe TIME_WAIT state. In this scenario, the connection tracking entry\nis evaluated as already confirmed. Previously, __nf_conncount_add()\nassumed that if a connection was confirmed and did not originate from\nthe loopback interface, it should skip the addition and return -EEXIST.\n\nSkipping the addition triggers a garbage collection run that cleans up\nthe TIME_WAIT connection. Consequently, the active connection count\ndrops to 0, which xt_connlimit mishandles, leading to the false rejection\nof the perfectly valid new connection.\n\nFix this by replacing the interface check with protocol-agnostic state\nchecks. We now skip the tree insertion and preserve the lockless garbage\ncollection optimization only if the connection is IPS_ASSURED. This\nallows early-confirmed setup packets (such as reused TIME_WAIT sockets\nor locally generated SYN-ACKs) to be properly evaluated and counted\nwithout falsely dropping. The goto check_connections path is maintained\nto ensure these setup packets are deduplicated correctly.\n\nThis has been tested with slowhttptest and HTTP server configured\nlocally to ensure we are not breaking soft-limiting scenarios for local\nor external connections. In addition, it was tested with a OVS zone\nlimit too.",
  "id": "CVE-2026-72418",
  "modified": "2026-08-18T03:31:09.764871091Z",
  "published": "2026-08-15T05:56:38.374Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/000ac6830b56499d6b65fd91486ce6689eb02be4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/329f2626ee5cb8fafdf6b58b624311529c57cb45"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3793d24de224943e0a6016bbeffb6f5c4cea2e3d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/abef7f817217fcb62c11821d6b895063eadb2828"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/be52572c6d55f677ba76869d3c63805c0d4891a3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c8b6f36f766991e3ebebec6596daee4b04dcbc49"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cbe2d14a7c5b1fc71821fbfee5c4963917411e92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ebfe8249ba79e4ff0f1e3aad8787b992ef27f026"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72418.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72418"
    },
    {
      "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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: nf_conncount: prevent connlimit drops for early confirmed ct"
}