Vulnerability · 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…
Published May 6, 2026 · catalog updated Sep 14, 2026 · linux kernel
Check if you run it
No confirmed exploitation is on record for CVE-2026-43198. EPSS is 0.30%. Act only if a listed version of linux kernel is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Critical9.8
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.30%
- Remediation
- Advisory link
- Affected products
- cpe linux/linux kernel
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe linux/linux kernel2.6.12
- cpe linux/linux kernel7.0
How to fix CVE-2026-43198
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-43198. EPSS is 0.30%. Act only if a listed version of linux kernel is installed.
Which versions are affected?
Compare what you have installed with linux/linux kernel 2.6.12; linux/linux kernel 7.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-362: Race Condition; CWE-821. EPSS 0.30%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
May 6, 2026 · NIST NVD
Detected
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 thing
Sep 14, 2026 · NIST NVD
Updated
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 thing
Sources
- CVE.orgVulnerability recordCVE-2026-43198
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-43198
30-day exploitation probability 0.3%
first.org - NIST NVDVulnerability recordCVE-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 fro
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.