{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7e0b2b57f01d183e1c84114f1f2287737358d748"
            },
            {
              "fixed": "c458fc1c278a65ad5381083121d39a479973ebed"
            },
            {
              "fixed": "c581e5c8f2b59158f62efe61c1a3dc36189081ff"
            },
            {
              "fixed": "f16fe84879a5280f05ebbcea593a189ba0f3e79a"
            },
            {
              "fixed": "070abdf1b04325b21a20a2a0c39a2208af107275"
            },
            {
              "fixed": "aa7cfa16f98f8ec3e6d47c34e1a8c1ae4b9b8b77"
            },
            {
              "fixed": "b42aca3660dc2627a29a38131597ca610dc451f9"
            },
            {
              "fixed": "d0983b48c10d1509fd795c155f8b1e832e1369ff"
            },
            {
              "fixed": "f8dca15a1b190787bbd03285304b569631160eda"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.19.0"
            },
            {
              "fixed": "5.10.253"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.203"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.169"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.135"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.82"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.23"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31665.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_ct: fix use-after-free in timeout object destroy\n\nnft_ct_timeout_obj_destroy() frees the timeout object with kfree()\nimmediately after nf_ct_untimeout(), without waiting for an RCU grace\nperiod. Concurrent packet processing on other CPUs may still hold\nRCU-protected references to the timeout object obtained via\nrcu_dereference() in nf_ct_timeout_data().\n\nAdd an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer\nfreeing until after an RCU grace period, matching the approach already\nused in nfnetlink_cttimeout.c.\n\nKASAN report:\n BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0\n Read of size 4 at addr ffff8881035fe19c by task exploit/80\n\n Call Trace:\n  nf_conntrack_tcp_packet+0x1381/0x29d0\n  nf_conntrack_in+0x612/0x8b0\n  nf_hook_slow+0x70/0x100\n  __ip_local_out+0x1b2/0x210\n  tcp_sendmsg_locked+0x722/0x1580\n  __sys_sendto+0x2d8/0x320\n\n Allocated by task 75:\n  nft_ct_timeout_obj_init+0xf6/0x290\n  nft_obj_init+0x107/0x1b0\n  nf_tables_newobj+0x680/0x9c0\n  nfnetlink_rcv_batch+0xc29/0xe00\n\n Freed by task 26:\n  nft_obj_destroy+0x3f/0xa0\n  nf_tables_trans_destroy_work+0x51c/0x5c0\n  process_one_work+0x2c4/0x5a0",
  "id": "CVE-2026-31665",
  "modified": "2026-07-08T05:36:57.050635615Z",
  "published": "2026-04-24T14:45:14.613Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/070abdf1b04325b21a20a2a0c39a2208af107275"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aa7cfa16f98f8ec3e6d47c34e1a8c1ae4b9b8b77"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b42aca3660dc2627a29a38131597ca610dc451f9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c458fc1c278a65ad5381083121d39a479973ebed"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c581e5c8f2b59158f62efe61c1a3dc36189081ff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d0983b48c10d1509fd795c155f8b1e832e1369ff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f16fe84879a5280f05ebbcea593a189ba0f3e79a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f8dca15a1b190787bbd03285304b569631160eda"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31665.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31665"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: nft_ct: fix use-after-free in timeout object destroy"
}