{
  "cveId": "CVE-2026-99201",
  "url": "https://patchblox.com/security/cve/CVE-2026-99201",
  "summary": "CVE-2026-99201 is fixed in linux on 1 platform by DEBIAN-CVE-2026-99201 (version 6.12.115-2), released November 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "netlink: avoid hashing the network namespace pointer",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  netlink: avoid hashing the network namespace pointer  The netlink rhashtable key includes a raw struct net pointer and a user-controlled port ID. Both /proc/net/netlink and socket diagnostics expose the table\u0027s bucket order. By binding and rebinding chosen NETLINK_USERSOCK port IDs, an unprivileged reader can distinguish equal buckets and recover the low bits of the Jenkins hash. Its 32-bit seed and the limited set of kernel-image slides can then be searched offline to recover the address of init_net.  Use the namespace\u0027s unique, non-address net_cookie in the comparison key instead. It is assigned before the per-net initializers run and remains unchanged for the namespace\u0027s lifetime. The lookup key and object hash are still built by netlink_compare_arg_init(), keeping lookup, insertion, removal and rehashing consistent while preserving namespace separation. Neither public table walker needs to change.  Reading the socket\u0027s namespace cookie in netlink_compare() is safe under RCU, including during namespace teardown. netlink_release() removes the socket from the hash table and defers its final put with call_rcu(). cleanup_net() runs the per-net exit methods and waits for outstanding RCU callbacks with rcu_barrier() before freeing namespace storage.  Unlike ns.ns_id, net_cookie is also available and initialized during setup_net() in older stable kernels, making the change straightforward to backport to v5.15 and later.",
  "published": "2026-10-28T11:17:41Z",
  "severity": "Low",
  "cvss": 3.3,
  "epss": 0.00171,
  "epssPercentile": 0.06497,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-99201",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-99201",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-99201",
      "released": "2026-11-03T18:58:21Z"
    }
  ],
  "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"
  }
}