{
  "cveId": "CVE-2026-53017",
  "url": "https://patchblox.com/security/cve/CVE-2026-53017",
  "summary": "CVE-2026-53017 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53017, released June 25, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "f2fs: fix data loss caused by incorrect use of nat_entry flag",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix data loss caused by incorrect use of nat_entry flag  Data loss can occur when fsync is performed on a newly created file (before any checkpoint has been written) concurrently with a checkpoint operation. The scenario is as follows:  create \u0026 write \u0026 fsync \u0027file A\u0027                 write checkpoint - f2fs_do_sync_file // inline inode  - f2fs_write_inode // inode folio is dirty                                                 - f2fs_write_checkpoint                                                  - f2fs_flush_merged_writes                                                  - f2fs_sync_node_pages                                                  - f2fs_flush_nat_entries  - f2fs_fsync_node_pages // no dirty node  - f2fs_need_inode_block_update // return false  SPO and lost \u0027file A\u0027  f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC flags for the nat_entry, but this does not mean that the checkpoint has actually completed successfully. However, f2fs_need_inode_block_update() checks these flags and incorrectly assumes that the checkpoint has finished.  The root cause is that the semantics of IS_CHECKPOINTED and HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully completes.  This patch modifies f2fs_need_inode_block_update() to acquire the sbi-\u003Enode_write lock before reading the nat_entry flags, ensuring that once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the checkpoint operation has already completed.",
  "published": "2026-06-24T17:17:13Z",
  "severity": "Critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00162,
  "epssPercentile": 0.05467,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53017",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-53017",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53017",
      "released": "2026-06-25T17:23:13Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.10-1",
      "fix": "DEBIAN-CVE-2026-53017",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53017",
      "released": "2026-06-25T17:23:13Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}