Is CVE-2026-43198 being actively exploited?

It is not currently in CISA's KEV catalog. Its EPSS exploitation probability is 0%.

What products does CVE-2026-43198 affect?

Tracked products affected include Linux Kernel. Check the version you run to see whether it is affected.

How do I fix CVE-2026-43198?

Apply the vendor fix promptly. An official patch or advisory is available. Upgrade affected products to a fixed version.

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CVE-2026-43198

Q: What is CVE-2026-43198?

CVE-2026-43198 is a critical-severity software vulnerability (CWE-362) with a CVSS score of 9.8. 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(),

CRITICAL severity · CVSS 9.8 · CWE-362

9.8CVSS CRITICAL

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

Exploit probability (EPSS)0%

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

Affected products we track (1)

Linux Kernel

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b ↗

CVE-2026-43198

Summary

Impact & exploitability

Affected products we track (1)

Recommendation

Additional information