CVE-2026-74268
Linux kernel vulnerability
- Published15 Aug 2026
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: clear sock_ops cb flags before force-closing a child socket A child socket inherits the listener's bpf_sock_ops_cb_flags via sk_clone_lock(). If its setup fails in tcp_v4_syn_recv_sock() / tcp_v6_syn_recv_sock(), the child is freed through put_and_exit, where inet_csk_prepare_forced_close() drops the socket lock and tcp_done() runs without it. If BPF_SOCK_OPS_STATE_CB_FLAG was inherited, tcp_done() -> tcp_set_state() calls tcp_call_bpf(), which expects the lock and trips sock_owned_by_me(): WARNING: include/net/sock.h:1799 at tcp_set_state+0x433/0x550 RIP: 0010:tcp_set_state+0x433/0x550 include/net/sock.h:1799 Call Trace: <IRQ> tcp_done+0xba/0x250 net/ipv4/tcp.c:5095 tcp_v4_syn_recv_sock+0x850/0xa50 net/ipv4/tcp_ipv4.c:1787 tcp_check_req+0xf30/0x1360 net/ipv4/tcp_minisocks.c:926 tcp_v4_rcv+0x1047/0x1b50 net/ipv4/tcp_ipv4.c:2164 </IRQ> The child is freed before it is ever established, so it should run no sock_ops callback. Clear its cb flags in inet_csk_prepare_for_destroy_sock(), the common point for the IPv4, IPv6 and chtls forced-close paths and for the MPTCP ->syn_recv_sock() failure path (dispose_child), which reaches tcp_done() on a child that was never established too.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- https://git.kernel.org/stable/c/5d5389b2c37ca00da61d1407618ebe15abae0c8b
- https://git.kernel.org/stable/c/71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f
- https://git.kernel.org/stable/c/8874dafc9099bc49c2e5ebba030f85d276421f92
- https://git.kernel.org/stable/c/990348e5bb457697c2f1f7f7b65154a3334d9d2b
- https://git.kernel.org/stable/c/9f30ba9aa0270a18fdd1e6cd426c480c35f7de9d
- https://git.kernel.org/stable/c/9fffa6465851a1910a6e9cb7272787dd615b26b1
- https://git.kernel.org/stable/c/ce311bd2e36596f0aa2c92ca86fb3e019ac57eae
- https://git.kernel.org/stable/c/fe23d56e9266d58ba5c380f1970118eedeee0b68
Frequently asked
Is CVE-2026-74268 being actively exploited?
CVE-2026-74268 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.71%.
How severe is CVE-2026-74268?
CVE-2026-74268 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.71% probability of exploitation.
How do I fix CVE-2026-74268?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-74268 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.