{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "3f3339885fb343b7b42d7c34717108ce07da24ae"
            },
            {
              "fixed": "8d9a79fbf5172d9c4c0146057af2360913265a11"
            },
            {
              "fixed": "ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"
            },
            {
              "fixed": "eb48730bb827d1550401a5d391903f9d90b493c8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.14.0"
            },
            {
              "fixed": "6.18.36"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53240.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix use-after-free on first_skb in __input_process_payload\n\n__input_process_payload() stores first_skb into xtfs-\u003era_newskb under\ndrop_lock when starting partial reassembly, then unlocks and breaks out\nof the processing loop. The post-loop check reads xtfs-\u003era_newskb\nwithout the lock to decide whether first_skb is still owned:\n\n    if (first_skb \u0026\u0026 first_iplen \u0026\u0026 !defer \u0026\u0026 first_skb != xtfs-\u003era_newskb)\n\nBetween spin_unlock and this read, a concurrent CPU running\niptfs_reassem_cont() (or the drop_timer hrtimer) can complete\nreassembly, NULL xtfs-\u003era_newskb, and free the skb. The check then\nevaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb\noperate on the freed skb — a use-after-free in skbuff_head_cache.\n\nReplace the unlocked read with a local bool that records whether\nfirst_skb was handed to the reassembly state in the current call. The\nflag is set after the existing spin_unlock, before the break, using the\npointer equality that is stable at that point (first_skb == skb iff\nfirst_skb was stored in ra_newskb).",
  "id": "CVE-2026-53240",
  "modified": "2026-07-10T03:54:28.913755170Z",
  "published": "2026-06-25T08:39:35.809Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8d9a79fbf5172d9c4c0146057af2360913265a11"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eb48730bb827d1550401a5d391903f9d90b493c8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53240.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53240"
    },
    {
      "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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload"
}