{
  "cveId": "CVE-2026-98975",
  "url": "https://patchblox.com/security/cve/CVE-2026-98975",
  "summary": "CVE-2026-98975 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-98975, released October 24, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "xfs: stop exchanging reflink flags when exchanging mappings",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  xfs: stop exchanging reflink flags when exchanging mappings  When an exchange covers both files from offset 0 to i_disk_size, xmi_can_exchange_reflink_flags() assumes every mapping moved and hands the reflink flag over to the other file.  That assumption is wrong.  A file can still own shared blocks past i_disk_size, e.g. after EXCHANGE_RANGE_TO_EOF sets a smaller size without unmapping anything.  The flag is cleared anyway, and the next write to such a block happens in place instead of CoW, corrupting the other file that shares it.  Commit a23eca88448e (\u0022xfs: fix exchange-range reflink flag clearing issue with INO1_WRITTEN\u0022) fixed one instance of this.  Rather than add another special case, stop moving the flags. xfs_exchmaps_ensure_reflink() already sets the flag on both inodes before the exchange, so both just keep it.  Nothing sets CLEAR_INO{1,2}_REFLINK anymore.  Intents logged by older kernels may still carry them; recovery already masks them off, so they stay in the log format mask and are ignored.  XFS_IOC_SWAPEXT has the same problem: it moves the reflink flag from one inode to the other along with the extents.  Just removing that is not enough here: the exchange path flags both inodes up front in xfs_exchmaps_ensure_reflink(), but swapext has no such step, so the inode receiving the shared extents would be left without the flag. Set it on both inodes instead, and make sure both have a CoW fork, since an inode with the reflink flag is expected to have one.  The flag now stays until FALLOC_FL_UNSHARE_RANGE, xfs_scrub, or a truncate to zero removes it.",
  "published": "2026-10-23T13:17:19Z",
  "severity": "Moderate",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00163,
  "epssPercentile": 0.05564,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98975",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-98975",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98975",
      "released": "2026-10-24T13:25:57Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.11-1",
      "fix": "DEBIAN-CVE-2026-98975",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98975",
      "released": "2026-10-24T13:25:57Z"
    }
  ],
  "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"
  }
}