{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "a3c90f7a2323b331ae816d5b0633e68148e25d04"
            },
            {
              "fixed": "64ac0cb574c740bf723affb79b646eeba920db6b"
            },
            {
              "fixed": "c5f91098edee98c015f78488460a0609e62582a5"
            },
            {
              "fixed": "4cd378423a33194a773c267fc58606d28fce95cf"
            },
            {
              "fixed": "747928b5d4ff8c8de55138a54c13980e4bb88578"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.16.0"
            },
            {
              "fixed": "6.12.113"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.56"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98851.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_flow_offload: drop flowtable reference on init error path\n\nnft_flow_offload_init() bumps the flowtable use count with\nnft_use_inc() before calling nf_ct_netns_get().  When the latter\nfails, the error is returned as-is and the reference is leaked.\n\nThe upper layers do not balance it either: nf_tables_newexpr()\nclears expr-\u003eops when the expression init callback fails, so the\nnft_expr_more() iteration in nft_rule_expr_deactivate() and\nnf_tables_rule_destroy() stops right before the failed expression\nand its -\u003edestroy callback, which would drop the reference, never\nruns.\n\nEach failed rule addition therefore leaks one flowtable reference\nand the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE\nkeeps reporting -EBUSY even though no rule references it.\n\nSave the nf_ct_netns_get() return value and undo the nft_use_inc()\nwhen it fails, restoring the inc/dec pairing within\nnft_flow_offload_init() itself.",
  "id": "CVE-2026-98851",
  "modified": "2026-10-19T02:31:00.069800773Z",
  "published": "2026-10-18T15:50:50.910Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4cd378423a33194a773c267fc58606d28fce95cf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/64ac0cb574c740bf723affb79b646eeba920db6b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/747928b5d4ff8c8de55138a54c13980e4bb88578"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c5f91098edee98c015f78488460a0609e62582a5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98851.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98851"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "netfilter: nft_flow_offload: drop flowtable reference on init error path"
}