{
  "cveId": "CVE-2025-71070",
  "url": "https://patchblox.com/security/cve/CVE-2025-71070",
  "summary": "CVE-2025-71070 is fixed in linux on 1 platform by DEBIAN-CVE-2025-71070 (version 6.18.3-1), released January 13, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  ublk: clean up user copy references on ublk serv...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ublk: clean up user copy references on ublk server exit  If a ublk server process releases a ublk char device file, any requests dispatched to the ublk server but not yet completed will retain a ref value of UBLK_REFCOUNT_INIT. Before commit e63d2228ef83 (\u0022ublk: simplify aborting ublk request\u0022), __ublk_fail_req() would decrement the reference count before completing the failed request. However, that commit optimized __ublk_fail_req() to call __ublk_complete_rq() directly without decrementing the request reference count. The leaked reference count incorrectly allows user copy and zero copy operations on the completed ublk request. It also triggers the WARN_ON_ONCE(refcount_read(\u0026io-\u003Eref)) warnings in ublk_queue_reinit() and ublk_deinit_queue(). Commit c5c5eb24ed61 (\u0022ublk: avoid ublk_io_release() called after ublk char dev is closed\u0022) already fixed the issue for ublk devices using UBLK_F_SUPPORT_ZERO_COPY or UBLK_F_AUTO_BUF_REG. However, the reference count leak also affects UBLK_F_USER_COPY, the other reference-counted data copy mode. Fix the condition in ublk_check_and_reset_active_ref() to include all reference-counted data copy modes. This ensures that any ublk requests still owned by the ublk server when it exits have their reference counts reset to 0.",
  "published": "2026-01-13T16:16:06Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00144,
  "epssPercentile": 0.03732,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.18.3-1",
      "fix": "DEBIAN-CVE-2025-71070",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-71070",
      "released": "2026-01-13T16:16:06Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-07T18:46:35Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}