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CVE-2026-45918

Estado: En análisisMedia (5.5)—

In the Linux kernel, the following vulnerability has been resolved:

ovpn: tcp - don't deref NULL sk_socket member after tcp_close()

When deleting a peer in case of keepalive expiration, the peer is removed from the OpenVPN hashtable and is temporary inserted in a "release list" for further processing.

This happens in: ovpn_peer_keepalive_work() unlock_ovpn(release_list)

This processing includes detaching from the socket being used to talk to this peer, by restoring its original proto and socket ops/callbacks.

In case of TCP it may happen that, while the peer is sitting in the release list, userspace decides to close the socket. This will result in a concurrent execution of:

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The last function call will set sk->sk_socket to NULL.

When the releasing routine is resumed, ovpn_tcp_socket_detach() will attempt to dereference sk->sk_socket to restore its original ops member. This operation will crash due to sk->sk_socket being NULL.

Fix this race condition by testing-and-accessing sk->sk_socket atomically under sk->sk_callback_lock.

Detalles técnicos trazas, registros y código del informe original
tcp_close(sk)
  __tcp_close(sk)
    sock_orphan(sk)
      sk_set_socket(sk, NULL)

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-45918",
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          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
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  "published": "2026-05-27T14:17:06.690",
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          "value": "CWE-476"
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: tcp - don't deref NULL sk_socket member after tcp_close()\n\nWhen deleting a peer in case of keepalive expiration, the peer is\nremoved from the OpenVPN hashtable and is temporary inserted in a\n\"release list\" for further processing.\n\nThis happens in:\novpn_peer_keepalive_work()\n  unlock_ovpn(release_list)\n\nThis processing includes detaching from the socket being used to\ntalk to this peer, by restoring its original proto and socket\nops/callbacks.\n\nIn case of TCP it may happen that, while the peer is sitting in\nthe release list, userspace decides to close the socket.\nThis will result in a concurrent execution of:\n\ntcp_close(sk)\n  __tcp_close(sk)\n    sock_orphan(sk)\n      sk_set_socket(sk, NULL)\n\nThe last function call will set sk->sk_socket to NULL.\n\nWhen the releasing routine is resumed, ovpn_tcp_socket_detach()\nwill attempt to dereference sk->sk_socket to restore its original\nops member. This operation will crash due to sk->sk_socket being NULL.\n\nFix this race condition by testing-and-accessing\nsk->sk_socket atomically under sk->sk_callback_lock."
    }
  ],
  "lastModified": "2026-06-24T17:22:46.393",
  "configurations": [
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        {
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          "operator": "OR"
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}