{
  "cveId": "CVE-2026-53320",
  "url": "https://patchblox.com/security/cve/CVE-2026-53320",
  "summary": "CVE-2026-53320 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53320, released June 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()  nilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks by comparing it with the current block number bd_blocknr. If they differ, the block is considered dead and skipped.  However, bd_oblocknr should never be 0 since block 0 typically stores the primary superblock and is never a valid GC target block. A corrupted ioctl request with bd_oblocknr set to 0 causes the comparison to incorrectly match when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing the dead block check and calling nilfs_bmap_mark() on a non-existent block. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering the WARN_ON(ret == -ENOENT).  Fix this by rejecting ioctl requests with bd_oblocknr set to 0 at the beginning of each iteration.  [ryusuke: slightly modified the commit message and comments for accuracy]",
  "published": "2026-06-26T20:17:25Z",
  "severity": "Moderate",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00173,
  "epssPercentile": 0.06744,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53320",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.176-1",
      "fix": "DEBIAN-CVE-2026-53320",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53320",
      "released": "2026-06-27T17:39:39Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.94-1",
      "fix": "DEBIAN-CVE-2026-53320",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53320",
      "released": "2026-06-27T17:39:39Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.10-1",
      "fix": "DEBIAN-CVE-2026-53320",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53320",
      "released": "2026-06-27T17:39:39Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}