{
  "cveId": "CVE-2026-53271",
  "url": "https://patchblox.com/security/cve/CVE-2026-53271",
  "summary": "CVE-2026-53271 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-53271, released June 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix NULL-deref of opinfo-\u003Econn in oplock/...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix NULL-deref of opinfo-\u003Econn in oplock/lease break notifiers  smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo-\u003Econn into a local with neither READ_ONCE() nor a NULL check.  Both run from oplock_break() after opinfo_get_list() has dropped ci-\u003Em_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op-\u003Econn = NULL under ci-\u003Em_lock within that window.  ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops.  Guard both reads the way compare_guid_key() already does: read opinfo-\u003Econn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks.  A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown.",
  "published": "2026-06-25T09:16:45Z",
  "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": 0.05384,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.94-1",
      "fix": "DEBIAN-CVE-2026-53271",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53271",
      "released": "2026-06-25T17:23:13Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.13-1",
      "fix": "DEBIAN-CVE-2026-53271",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-53271",
      "released": "2026-06-25T17:23:13Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}