{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "fa5e08156335d0687c85b4e724db9448fb166601"
            },
            {
              "fixed": "0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934"
            },
            {
              "fixed": "883962731420ec271ed8c1cd76524f4b17faa982"
            },
            {
              "fixed": "2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63"
            },
            {
              "fixed": "bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb"
            },
            {
              "fixed": "55287a3555ff0515b3aff181d2c08c0462a41709"
            },
            {
              "fixed": "e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad"
            },
            {
              "fixed": "74580fdf022909e184223cacc364feb826982d96"
            },
            {
              "fixed": "d8202786b3d75125c84ebc4de6d946f92fde0ee8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.26"
            },
            {
              "fixed": "5.10.261"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64323.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate VAT header length against the VAT inode size\n\nudf_load_vat() takes the virtual partition's start offset straight from\nthe on-disk VAT 2.0 header without checking it against the VAT inode\nsize:\n\n\tmap-\u003es_type_specific.s_virtual.s_start_offset =\n\t\tle16_to_cpu(vat20-\u003elengthHeader);\n\tmap-\u003es_type_specific.s_virtual.s_num_entries =\n\t\t(sbi-\u003es_vat_inode-\u003ei_size -\n\t\t\tmap-\u003es_type_specific.s_virtual.s_start_offset) \u003e\u003e 2;\n\nlengthHeader is a fully attacker-controlled 16-bit value.  If it exceeds\nthe VAT inode size, the s_num_entries subtraction underflows to a huge\ncount, which defeats the \"block \u003e s_num_entries\" bound in\nudf_get_pblock_virt15(); and on the ICB-inline path that function reads\n\n\t((__le32 *)(iinfo-\u003ei_data + s_start_offset))[block]\n\nso a large s_start_offset indexes past the inode's in-ICB data.  Mounting\na crafted UDF image with a virtual (VAT) partition then triggers an\nout-of-bounds read.\n\nReject a VAT whose header length does not leave room for at least one\nentry within the VAT inode.",
  "id": "CVE-2026-64323",
  "modified": "2026-07-28T03:55:46.673539442Z",
  "published": "2026-07-25T08:49:51.097Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55287a3555ff0515b3aff181d2c08c0462a41709"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/74580fdf022909e184223cacc364feb826982d96"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/883962731420ec271ed8c1cd76524f4b17faa982"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d8202786b3d75125c84ebc4de6d946f92fde0ee8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64323.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64323"
    },
    {
      "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:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "udf: validate VAT header length against the VAT inode size"
}