{
  "cveId": "CVE-2026-43421",
  "url": "https://patchblox.com/security/cve/CVE-2026-43421",
  "summary": "CVE-2026-43421 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-43421, released May 15, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "usb: gadget: f_ncm: Fix net_device lifecycle with device_move",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  usb: gadget: f_ncm: Fix net_device lifecycle with device_move  The network device outlived its parent gadget device during disconnection, resulting in dangling sysfs links and null pointer dereference problems.  A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1] was reverted due to power management ordering concerns and a NO-CARRIER regression.  A subsequent attempt to defer net_device allocation to bind [2] broke 1:1 mapping between function instance and network device, making it impossible for configfs to report the resolved interface name. This results in a regression where the DHCP server fails on pmOS.  Use device_move to reparent the net_device between the gadget device and /sys/devices/virtual/ across bind/unbind cycles. This preserves the network interface across USB reconnection, allowing the DHCP server to retain their binding.  Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use __free(detach_gadget) macro to undo attachment on bind failure. The bind_count ensures device_move executes only on the first bind.  [1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/ [2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/",
  "published": "2026-05-08T15:16:54Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00123,
  "epssPercentile": 0.02032,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43421",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.176-1",
      "fix": "DEBIAN-CVE-2026-43421",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-43421",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.85-1",
      "fix": "DEBIAN-CVE-2026-43421",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-43421",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.19.10-1",
      "fix": "DEBIAN-CVE-2026-43421",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-43421",
      "released": "2026-05-15T16:01:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T19:38:12Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}