{
  "cveId": "CVE-2026-63817",
  "url": "https://patchblox.com/security/cve/CVE-2026-63817",
  "summary": "CVE-2026-63817 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-63817, released July 20, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  f2fs: validate compress cache inode only when en...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  f2fs: validate compress cache inode only when enabled  F2FS_COMPRESS_INO() uses NM_I(sbi)-\u003Emax_nid as the synthetic inode number for the compressed page cache inode. That inode only exists when the compress_cache mount option is enabled.  When compress_cache is disabled, max_nid is outside the valid inode range. A corrupted directory entry that points to ino == max_nid should therefore be rejected by f2fs_check_nid_range(). However, is_meta_ino() currently treats F2FS_COMPRESS_INO() as a meta inode unconditionally, so f2fs_iget() bypasses do_read_inode() and its nid range check, and instantiates a fake internal inode instead.  Gate the compressed cache inode case on COMPRESS_CACHE, matching f2fs_init_compress_inode(). With compress_cache disabled, ino == max_nid now follows the normal inode path and is rejected as an out-of-range nid.",
  "published": "2026-07-19T12:16:54Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00134,
  "epssPercentile": 0.02919,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.177-1",
      "fix": "DEBIAN-CVE-2026-63817",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63817",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.95-1",
      "fix": "DEBIAN-CVE-2026-63817",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63817",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.3-1",
      "fix": "DEBIAN-CVE-2026-63817",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63817",
      "released": "2026-07-20T12:58:36Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-10T01:44:33Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}