{
  "cveId": "CVE-2026-64159",
  "url": "https://patchblox.com/security/cve/CVE-2026-64159",
  "summary": "CVE-2026-64159 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-64159, released July 20, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  netfs: Fix zeropoint update where i_size \u003E remot...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  netfs: Fix zeropoint update where i_size \u003E remote_i_size  Fix the update of the zero point[*] by netfs_release_folio() when there is uncommitted data in the pagecache beyond the folio being released but the on-server EOF is in this folio (ie. i_size \u003E remote_i_size).  The update needs to limit zero_point to remote_i_size, not i_size as i_size is a local phenomenon reflecting updates made locally to the pagecache, not stuff written to the server.  remote_i_size tracks the server\u0027s i_size.  [*] The zero point is the file position from which we can assume that the     server will just return zeros, so we can avoid generating reads.  Note that netfs_invalidate_folio() probably doesn\u0027t need fixing as zero_point should be updated by setattr after truncation or fallocate.  Found with:      fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \\         /xfstest.test/junk --replay-ops=junk.fsxops  using the following as junk.fsxops:      truncate 0x0 0x1bbae 0x82864     write 0x3ef2e 0xf9c8 0x1bbae     write 0x67e05 0xcb5a 0x4e8f6     mapread 0x57781 0x85b6 0x7495f     copy_range 0x5d3d 0x10329 0x54fac 0x7495f     write 0x64710 0x1c2b 0x7495f     mapread 0x64000 0x1000 0x7495f  on cifs with the default cache option.  It shows read-gaps on folio 0x64 failing with a short read (ie. it hits EOF) if the FMODE_READ check is commented out in netfs_perform_write():                  if (//(file-\u003Ef_mode \u0026 FMODE_READ) ||                     netfs_is_cache_enabled(ctx)) {  and no fscache.  This was initially found with the generic/522 xfstest.",
  "published": "2026-07-19T16:17:57Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00162,
  "epssPercentile": 0.0538,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-64159",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64159",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.12-1",
      "fix": "DEBIAN-CVE-2026-64159",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64159",
      "released": "2026-07-20T12:58:36Z"
    }
  ],
  "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"
  }
}