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

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.

Published: 2026-05-27 Last update: 2026-05-27 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2026-45918 is rated Low Risk (4.5/100): low exploitation likelihood (EPSS 0.02%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-45918

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-45918

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2026-45918

GitHub Security Advisory for CVE-2026-45918

GHSA-478p-qchq-q398 · Severity: unknown — In the Linux kernel, the following vulnerability has been resolved: ovpn: tcp - don't deref NULL...

OS Trackers for CVE-2026-45918

vendor priority summary link
debian unimportant CVE-2026-45918 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-45918
redhat https://access.redhat.com/security/cve/CVE-2026-45918
suse https://www.suse.com/security/cve/CVE-2026-45918/
ubuntu medium CVE-2026-45918 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1422 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1024, ignored 169, not-affected 125, released 84, needed 19, needs-triage 1. https://ubuntu.com/security/CVE-2026-45918

Affected software / configurations for CVE-2026-45918

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-45918

cvelogic Threat Intelligence