{
  "cveId": "CVE-2026-31718",
  "url": "https://patchblox.com/security/cve/CVE-2026-31718",
  "summary": "CVE-2026-31718 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-31718, released May 15, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger  When a durable file handle survives session disconnect (TCP close without SMB2_LOGOFF), session_fd_check() sets fp-\u003Econn = NULL to preserve the handle for later reconnection. However, it did not clean up the byte-range locks on fp-\u003Elock_list.  Later, when the durable scavenger thread times out and calls __ksmbd_close_fd(NULL, fp), the lock cleanup loop did:      spin_lock(\u0026fp-\u003Econn-\u003Ellist_lock);  This caused a slab use-after-free because fp-\u003Econn was NULL and the original connection object had already been freed by ksmbd_tcp_disconnect().  The root cause is asymmetric cleanup: lock entries (smb_lock-\u003Eclist) were left dangling on the freed conn-\u003Elock_list while fp-\u003Econn was nulled out.  To fix this issue properly, we need to handle the lifetime of smb_lock-\u003Eclist across three paths:  - Safely skip clist deletion when list is empty and fp-\u003Econn is NULL.  - Remove the lock from the old connection\u0027s lock_list in    session_fd_check()  - Re-add the lock to the new connection\u0027s lock_list in    ksmbd_reopen_durable_fd().",
  "published": "2026-05-01T14:16:21Z",
  "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": 0.00356,
  "epssPercentile": 0.29563,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31718",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.85-1",
      "fix": "DEBIAN-CVE-2026-31718",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31718",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.3-1",
      "fix": "DEBIAN-CVE-2026-31718",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31718",
      "released": "2026-05-15T16:01:09Z"
    }
  ],
  "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"
  }
}