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udf: validate VAT header length against the VAT inode size

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: udf: validate VAT header length against the VAT inode size udf_load_vat() takes the virtual partition's start offset straight from the on-disk VAT 2.0 header without checking it against the VAT inode size: map->s_type_specific.s_virtual.s_start_offset = le16_to_cpu(vat20->lengthHeader); map->s_type_specific.s_virtual.s_num_entries = (sbi->s_vat_inode->i_size - map->s_type_specific.s_virtual.s_start_offset) >> 2; lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds the VAT inode size, the s_num_entries subtraction underflows to a huge count, which defeats the "block > s_num_entries" bound in udf_get_pblock_virt15(); and on the ICB-inline path that function reads ((__le32 *)(iinfo->i_data + s_start_offset))[block] so a large s_start_offset indexes past the inode's in-ICB data. Mounting a crafted UDF image with a virtual (VAT) partition then triggers an out-of-bounds read. Reject a VAT whose header length does not leave room for at least one entry within the VAT inode.

Announced Source revision 1
Original source ↗

CVE-2026-64323

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-64323

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "883962731420ec271ed8c1cd76524f4b17faa982",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "55287a3555ff0515b3aff181d2c08c0462a41709",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "74580fdf022909e184223cacc364feb826982d96",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "fa5e08156335d0687c85b4e724db9448fb166601",
        "lessThan": "d8202786b3d75125c84ebc4de6d946f92fde0ee8",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/udf/super.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.26"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.26",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.261",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.212",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.178",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.145",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.96",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.39",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.4",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/udf/super.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-64323

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#41009 · Revision 1
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Publisher date
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