{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "d67ae825a59d639e4d8b82413af84d854617a87e"
            },
            {
              "fixed": "7779c85028a0676fb190cde4f0c540f4f8e97761"
            },
            {
              "fixed": "d8c90c7cc061265d5f2813a1f5c82ef2f4707e67"
            },
            {
              "fixed": "2131ed64b767ffa8bcdb3677d90f3964e39aabc8"
            },
            {
              "fixed": "2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.38"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53392.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4/flexfiles: reject zero filehandle version count\n\nff_layout_alloc_lseg() decodes the filehandle-version array count\nfrom the flexfiles layout body. The value is used as the count for\nkzalloc_objs(), and the current code only rejects NULL.\n\nA zero count yields ZERO_SIZE_PTR, which can be stored in\ndss_info-\u003efh_versions even though later flexfiles paths assume that at\nleast one filehandle version exists.\n\nReject fh_count == 0 before the allocation, matching the existing zero\nversion_count validation in the flexfiles GETDEVICEINFO parser.\n\nA QEMU/KASAN run with a malformed flexfiles layout hit:\n\n  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n  RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750\n  ff_layout_encode_layoutreturn+0x683/0x970\n  nfs4_xdr_enc_layoutreturn+0x278/0x3a0\n  Kernel panic - not syncing: Fatal exception\n\nThe patched kernel rejects the malformed layout without KASAN/oops/panic,\nand a valid fh_count=1 regression still opens, reads, and unmounts cleanly.",
  "id": "CVE-2026-53392",
  "modified": "2026-07-21T03:42:00.734939854Z",
  "published": "2026-07-19T12:01:56.101Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2131ed64b767ffa8bcdb3677d90f3964e39aabc8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7779c85028a0676fb190cde4f0c540f4f8e97761"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d8c90c7cc061265d5f2813a1f5c82ef2f4707e67"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53392.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53392"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "NFSv4/flexfiles: reject zero filehandle version count"
}