{
  "cveId": "CVE-2026-97971",
  "url": "https://patchblox.com/security/cve/CVE-2026-97971",
  "summary": "CVE-2026-97971 is fixed in linux on 1 platform by DEBIAN-CVE-2026-97971 (version 7.2.7-1), released October 2, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  nstree: check listing permission before taking a...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  nstree: check listing permission before taking a namespace reference  legitimize_ns() takes a reference on the candidate namespace before may_list_ns() has decided whether the caller may see it. The __free(ns_put) cleanup on the denied path can drop the last reference to a mount namespace while we still hold the rcu read lock, and put_mnt_ns() may sleep there. This is the same problem commit 2ec2aff3c8e2 (\u0022ns: make sure reference are dropped outside of rcu lock\u0022) fixed for the put_user() path. Neither ns_requested() nor may_list_ns() needs a reference, both only look at the namespace type and at the caller\u0027s own namespaces, so do the checks first and take the reference last.  Splat:    Voluntary context switch within RCU read-side critical section!   WARNING: kernel/rcu/tree_plugin.h:332 at rcu_note_context_switch\u002B0x238/0x2a0, CPU#5: a/3442   CPU: 5 UID: 1000 PID: 3442 Comm: a Not tainted 7.0.0-30-generic #30-Ubuntu PREEMPT(lazy)   RIP: 0010:rcu_note_context_switch\u002B0x238/0x2a0   Call Trace:    \u003CTASK\u003E    __schedule\u002B0xcf/0x650    schedule\u002B0x27/0x90    schedule_preempt_disabled\u002B0x15/0x30    __mutex_lock.constprop.0\u002B0x550/0xaf0    __mutex_lock_slowpath\u002B0x13/0x20    mutex_lock\u002B0x3b/0x50    exp_funnel_lock\u002B0xb2/0x260    synchronize_rcu_expedited\u002B0xe7/0x220    namespace_unlock\u002B0x26a/0x320    put_mnt_ns\u002B0xd3/0x120    mntns_put\u002B0xe/0x20    do_listns\u002B0x13e/0x560    __do_sys_listns\u002B0x126/0x2d0    __x64_sys_listns\u002B0x20/0x30    x64_sys_call\u002B0x2366/0x2390    do_syscall_64\u002B0x105/0x5a0    entry_SYSCALL_64_after_hwframe\u002B0x76/0x7e    \u003C/TASK\u003E",
  "published": "2026-09-25T11:17:24Z",
  "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": 0.0012,
  "epssPercentile": 0.0186,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.7-1",
      "fix": "DEBIAN-CVE-2026-97971",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-97971",
      "released": "2026-10-02T21:04:56Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}