{
  "cveId": "CVE-2026-98987",
  "url": "https://patchblox.com/security/cve/CVE-2026-98987",
  "summary": "CVE-2026-98987 is fixed in linux on 1 platform by DEBIAN-CVE-2026-98987 (version 7.2.11-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  namespace: look at the topmost mount for a mount...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  namespace: look at the topmost mount for a mount namespace file  attach_recursive_mnt() preallocates a mountpoint for the root of the topmost mount of the source so that a mount that already sits at the destination can be put on top of the source or on top of one of its propagated copies.  The copies are made without CL_COPY_MNT_NS_FILE so their chain of overmounts is shorter than the source\u0027s. It ends below the first bind mount of a mount namespace file. So while the loop walks up the chain of the source it remembers the mountpoint of that mount in \u0022shorter\u0022 and the existing mount is put there for the copies.  But the loop ends at the topmost mount without ever looking at it. If the topmost mount is the only mount namespace file in the chain \u0022shorter\u0022 stays NULL and mnt_change_mountpoint() attaches the existing mount of the copy below the root of the mount namespace file. That\u0027s a dentry of nsfs. No path walk in the copy\u0027s mount namespace ever gets there. The mount is gone until its parent goes and the copy that took its place can\u0027t be unmounted synchronously because it has a child:    S      bind mount of a file   N      bind mount of a mount namespace file on top of S   A      shared mount, B a slave of A, Q mounted on B/file    move_mount(S, A/file)   cat B/file          -\u003E the content of S instead of Q   umount B/file       -\u003E EBUSY  Look at every mount of the chain including the topmost one.",
  "published": "2026-10-23T13:17:20Z",
  "severity": "",
  "epss": 0.00166,
  "epssPercentile": 0.05937,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.11-1",
      "fix": "DEBIAN-CVE-2026-98987",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98987",
      "released": "2026-10-24T13:25:57Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}