CVE-2026-43198

In the Linux kernel, the following vulnerability has been resolved: tcp: fix potential race in tcp_v6_syn_recv_sock() Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 22% of CVEs (scores of 2026-10-25)

CWEs

CWE-362, CWE-821

Published

2026-05-06

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b
• https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae
• https://git.kernel.org/stable/c/9ed654e340f4c73bc6f0af2fbc90ac293e645ce0
• https://git.kernel.org/stable/c/a7e761ba55efaa9c49e0afdd304bb78167af3429
• https://git.kernel.org/stable/c/aef4a9ae95d1bc4f7897065011e6261026719aeb

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