{
  "cveId": "CVE-2026-53198",
  "url": "https://patchblox.com/security/cve/CVE-2026-53198",
  "summary": "CVE-2026-53198 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53198, released June 25, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL  A deferred byte-range lock (an SMB2_LOCK that blocks) registers an async work on conn-\u003Easync_requests via setup_async_work(), with cancel_fn = smb2_remove_blocked_lock and cancel_argv[0] pointing at the struct file_lock.  When the request is cancelled, the worker frees the file_lock with locks_free_lock() and takes the cancelled early-exit, which \u0022goto out\u0022s and never reaches release_async_work() -- the only site that unlinks the work from conn-\u003Easync_requests and clears cancel_fn/cancel_argv. The work therefore stays matchable on async_requests with a live cancel_fn pointing at the freed file_lock, until connection teardown finally runs release_async_work().  smb2_cancel() fires cancel_fn unconditionally with no state guard, so a second SMB2_CANCEL for the same AsyncId, arriving in that window, re-runs smb2_remove_blocked_lock() on the freed file_lock -- a slab use-after-free:    BUG: KASAN: slab-use-after-free in __locks_delete_block     __locks_delete_block     locks_delete_block     ksmbd_vfs_posix_lock_unblock     smb2_remove_blocked_lock     smb2_cancel                 \u003C- 2nd SMB2_CANCEL fires cancel_fn     handle_ksmbd_work   Allocated by ...: locks_alloc_lock \u003C- smb2_lock   Freed by ...:     locks_free_lock  \u003C- smb2_lock (cancelled branch)   ... cache file_lock_cache of size 192  Reproduced on mainline with KASAN by an authenticated SMB client.  Skip a work whose state is already KSMBD_WORK_CANCELLED so its cancel callback cannot be fired a second time.",
  "published": "2026-06-25T09:16:37Z",
  "severity": "Important",
  "cvss": 8.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00445,
  "epssPercentile": 0.38943,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53198",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.176-1",
      "fix": "DEBIAN-CVE-2026-53198",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53198",
      "released": "2026-06-25T17:23:13Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.94-1",
      "fix": "DEBIAN-CVE-2026-53198",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53198",
      "released": "2026-06-25T17:23:13Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.13-1",
      "fix": "DEBIAN-CVE-2026-53198",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53198",
      "released": "2026-06-25T17:23:13Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}