Vulnerability Details CVE-2026-45918
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:
tcp_close(sk)
__tcp_close(sk)
sock_orphan(sk)
sk_set_socket(sk, NULL)
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 5.8%
CVSS Severity
CVSS v3 Score 5.5
Products affected by CVE-2026-45918
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cpe:2.3:o:linux:linux_kernel:6.16
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cpe:2.3:o:linux:linux_kernel:6.16.1
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cpe:2.3:o:linux:linux_kernel:6.16.10
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cpe:2.3:o:linux:linux_kernel:6.16.11
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cpe:2.3:o:linux:linux_kernel:6.16.12
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cpe:2.3:o:linux:linux_kernel:6.16.2
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cpe:2.3:o:linux:linux_kernel:6.16.3
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cpe:2.3:o:linux:linux_kernel:6.16.4
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cpe:2.3:o:linux:linux_kernel:6.16.5
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cpe:2.3:o:linux:linux_kernel:6.16.6
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cpe:2.3:o:linux:linux_kernel:6.16.7
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cpe:2.3:o:linux:linux_kernel:6.16.8
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cpe:2.3:o:linux:linux_kernel:6.16.9
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cpe:2.3:o:linux:linux_kernel:6.17
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cpe:2.3:o:linux:linux_kernel:6.17.1
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cpe:2.3:o:linux:linux_kernel:6.17.10
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cpe:2.3:o:linux:linux_kernel:6.17.11
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cpe:2.3:o:linux:linux_kernel:6.17.12
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cpe:2.3:o:linux:linux_kernel:6.17.13
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cpe:2.3:o:linux:linux_kernel:6.17.2
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cpe:2.3:o:linux:linux_kernel:6.17.3
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cpe:2.3:o:linux:linux_kernel:6.17.4
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cpe:2.3:o:linux:linux_kernel:6.17.5
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cpe:2.3:o:linux:linux_kernel:6.17.6
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cpe:2.3:o:linux:linux_kernel:6.17.7
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cpe:2.3:o:linux:linux_kernel:6.17.8
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cpe:2.3:o:linux:linux_kernel:6.17.9
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cpe:2.3:o:linux:linux_kernel:6.18
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cpe:2.3:o:linux:linux_kernel:6.18.1
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cpe:2.3:o:linux:linux_kernel:6.18.10
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cpe:2.3:o:linux:linux_kernel:6.18.11
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cpe:2.3:o:linux:linux_kernel:6.18.13
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cpe:2.3:o:linux:linux_kernel:6.18.2
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cpe:2.3:o:linux:linux_kernel:6.18.3
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cpe:2.3:o:linux:linux_kernel:6.18.4
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cpe:2.3:o:linux:linux_kernel:6.18.5
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cpe:2.3:o:linux:linux_kernel:6.18.6
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cpe:2.3:o:linux:linux_kernel:6.18.7
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cpe:2.3:o:linux:linux_kernel:6.18.8
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cpe:2.3:o:linux:linux_kernel:6.18.9
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.3