Medium 5.5Published May 27, 2026

CVE-2026-45918ovpn: tcp - don't deref NULL sk_socket member after tcp_close()

Updated under an hour ago (Oct 26, 2026, 3:00 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Undergoing Analysis
Record last updated: May 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 11851cbd60ea1e5abbd97619d69845ead99303d6 before f998b2c4bec487063a586695159f9a1856e81c56; from 11851cbd60ea1e5abbd97619d69845ead99303d6 before b9142cf4e066c825ec68752a7dcaceda700bbe26; from 11851cbd60ea1e5abbd97619d69845ead99303d6 before 94560267d6c41b1ff3fafbab726e3f8a55a6af34	CNA record
linux linux_kernel linux:linux_kernel	from 6.16 before 6.18.14; from 6.19 before 6.19.4	NVD

References

References

https://git.kernel.org/stable/c/f998b2c4bec487063a586695159f9a1856e81c56	patch
https://git.kernel.org/stable/c/b9142cf4e066c825ec68752a7dcaceda700bbe26	patch
https://git.kernel.org/stable/c/94560267d6c41b1ff3fafbab726e3f8a55a6af34	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.