{
  "cveId": "CVE-2026-89546",
  "url": "https://patchblox.com/security/cve/CVE-2026-89546",
  "summary": "CVE-2026-89546 is fixed in linux on 1 platform by DEBIAN-CVE-2026-89546 (version 7.2.6-1), released September 23, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  SUNRPC: close backchannel before destroying call...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  SUNRPC: close backchannel before destroying callback service  A backchannel receive can complete a request while the NFS callback service is being torn down.  xprt_complete_bc_request() removes the request from bc_pa_list, drops bc_alloc_count, marks the request in use, and then asks xprt_enqueue_bc_request() to hand it to the callback service.  If teardown has already cleared xprt-\u003Ebc_serv, xprt_enqueue_bc_request() currently returns without enqueueing or freeing the committed request. The xprt_get() taken on entry is leaked as well.  If the producer wins the race before bc_serv is cleared, it can also enqueue onto sv_cb_list after nfs_callback_down() has stopped the callback threads, leaving the request linked to a svc_serv that is about to be freed.  Close the producer side before callback threads are stopped.  Add xprt_svc_shutdown_bc() to clear xprt-\u003Ebc_serv under bc_pa_lock, and call it on callback shutdown and callback-start failure before stopping the service threads.  Requests that lose the NULL transition in xprt_enqueue_bc_request() are released through the normal backchannel free path after balancing bc_slot_count.  Finally, drain any remaining sv_cb_list requests after the callback threads have stopped and before svc_destroy() frees the service.",
  "published": "2026-09-11T20:19:37Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00553,
  "epssPercentile": 0.4646,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-89546",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-89546",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}