{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ebfbe67568a734a449203097b02c4ab884257535"
            },
            {
              "fixed": "a7fdd86c386b7f7cc72a126389c2cdb55d035221"
            },
            {
              "fixed": "1f69c570a73f2dedf75ea5166d47622d5fa958c1"
            },
            {
              "fixed": "fec9b1de0d02de8dafa3cc344bcb91cf28660643"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97609.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: cttimeout: prevent UAF during module unload\n\nnf_ct_set_timeout() protects the timeout hook dereference and policy lookup\nwith rcu_read_lock(). cttimeout_exit(), however, unregisters the per-net\noperations before it clears the hook.\n\nThis allows the following interleaving:\n\n  CPU 0                              CPU 1\n  cttimeout_exit()                   nf_ct_set_timeout()\n    unregister_pernet_subsys()         rcu_read_lock()\n      kfree(pernet)                     h = nf_ct_timeout_hook\n                                        h-\u003etimeout_find_get()\n                                          nfct_timeout_pernet()\n\nThe hook still points to ctnl_timeout_find_get() when CPU 1 looks up the\nalready freed per-net timeout list. KASAN reported:\n\n  BUG: KASAN: slab-use-after-free in ctnl_timeout_find_get\n  Read of size 8 by task poc/90\n  Call Trace:\n   ctnl_timeout_find_get+0x271/0x2a0 [nfnetlink_cttimeout]\n   nf_ct_set_timeout+0x7b/0x3c0\n   xt_ct_tg_check+0x724/0xb20\n   xt_check_target+0x234/0xa90\n   do_ipt_set_ctl+0x570/0x1270\n  Allocated by task 89:\n   __kmalloc_noprof+0x16e/0x460\n   ops_init+0x6d/0x420\n   register_pernet_operations+0x2f6/0x670\n  Freed by task 91:\n   kfree+0x131/0x390\n   ops_undo_list+0x3d4/0x730\n   unregister_pernet_operations+0x232/0x490\n   unregister_pernet_subsys+0x1c/0x30\n   cttimeout_exit+0x52/0x970 [nfnetlink_cttimeout]\n\nClear the hook and wait for existing readers before unregistering the\nper-net operations. This blocks new policy lookups and ensures readers that\nobserved the hook finish before the per-net storage is freed.",
  "id": "CVE-2026-97609",
  "modified": "2026-09-27T03:30:44.526198121Z",
  "published": "2026-09-25T10:22:19.627Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1f69c570a73f2dedf75ea5166d47622d5fa958c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a7fdd86c386b7f7cc72a126389c2cdb55d035221"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fec9b1de0d02de8dafa3cc344bcb91cf28660643"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97609.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97609"
    },
    {
      "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:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: cttimeout: prevent UAF during module unload"
}