{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "c31b70c9968fe9c4194d1b5d06d07596a3b680de"
            },
            {
              "fixed": "fad6d429651e748365e93ca54645accc212f0018"
            },
            {
              "fixed": "c5b4da1f403a658c1c19766be2b426003ada419f"
            },
            {
              "fixed": "71d45049b0d631dfdbf3c65305f7fca676de023b"
            },
            {
              "fixed": "e3ea71cb1408a013ed4e8a757b815f1a919324bd"
            },
            {
              "fixed": "631aa4cb45099f09e9385dd786bd291c6270bfc4"
            },
            {
              "fixed": "0f87720c7e4bcab07c24888b3cf12bfe857bb90e"
            },
            {
              "fixed": "fe99bbeee5c5dbd3abc30721a8079ced59649d97"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.222"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.189"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.158"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.55"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98374.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()\n\nWhen tcp_send_synack() replaces the cloned SYN skb at the head of the\nretransmit queue with a copy, it frees the original with\ntcp_rtx_queue_unlink_and_free() and only repairs tp-\u003ehighest_sack.\ntp-\u003eretransmit_skb_hint keeps pointing at the freed\nskbuff_fclone_cache object.\n\nThe dangling hint is read in tcp_verify_retransmit_hint() and used as\nthe root of the rbtree walk in tcp_xmit_retransmit_queue().  An\nunprivileged TFO client (sendmsg(MSG_FASTOPEN)) can arm the hint with\nan attacker-supplied ICMP fragmentation-needed message, after which a\nsimultaneous open frees the armed SYN skb:\n\n  BUG: KASAN: slab-use-after-free in tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316)\n  Read of size 4 at addr ffff88800604d928 by task swapper/1/0\n  Call Trace:\n   tcp_mark_skb_lost (net/ipv4/tcp_input.c:1316)\n   tcp_simple_retransmit (net/ipv4/tcp_input.c:3158)\n   tcp_v4_err (net/ipv4/tcp_ipv4.c:587)\n\nSync the hint to the copy.",
  "id": "CVE-2026-98374",
  "modified": "2026-10-09T02:30:43.680530511Z",
  "published": "2026-10-07T13:01:48.600Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f87720c7e4bcab07c24888b3cf12bfe857bb90e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/631aa4cb45099f09e9385dd786bd291c6270bfc4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/71d45049b0d631dfdbf3c65305f7fca676de023b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c5b4da1f403a658c1c19766be2b426003ada419f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3ea71cb1408a013ed4e8a757b815f1a919324bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fad6d429651e748365e93ca54645accc212f0018"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe99bbeee5c5dbd3abc30721a8079ced59649d97"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98374.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98374"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "tcp: fix use-after-free of retransmit_skb_hint in tcp_send_synack()"
}