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CVE-2026-74268

CRITICALCVSS 9.8/10EPSS 0.71%

Last modified

CVE-2026-74268 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 0.71% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.71%

52.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= d44874910a26f3a8f81edf873a2473363f07f660, < 5d5389b2c37ca00da61d1407618ebe15abae0c8b; >= d44874910a26f3a8f81edf873a2473363f07f660, < 9f30ba9aa0270a18fdd1e6cd426c480c35f7de9d; >= d44874910a26f3a8f81edf873a2473363f07f660, < 71e9c53220abd7f5a45aa4d5e5b420d3479f3a4f; >= d44874910a26f3a8f81edf873a2473363f07f660, < 9fffa6465851a1910a6e9cb7272787dd615b26b1; >= d44874910a26f3a8f81edf873a2473363f07f660, < fe23d56e9266d58ba5c380f1970118eedeee0b68; >= d44874910a26f3a8f81edf873a2473363f07f660, < ce311bd2e36596f0aa2c92ca86fb3e019ac57eae; >= d44874910a26f3a8f81edf873a2473363f07f660, < 8874dafc9099bc49c2e5ebba030f85d276421f92; >= d44874910a26f3a8f81edf873a2473363f07f660, < 990348e5bb457697c2f1f7f7b65154a3334d9d2b
LinuxLinux4.16

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-74268?
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.
How severe is CVE-2026-74268?
CVE-2026-74268 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.
How do I fix CVE-2026-74268?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST