What is CVE-2026-43198?

CVE-2026-43198 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, classified as a Race Condition flaw (CWE-362), affecting Linux kernel versions from 2.6.12 onward and patched in 6.18.16, 6.19.6 and 7.0. CVE-2026-43198 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43198?

CVE-2026-43198 has a CVSS score of 9.8 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-43198?

Yes, CVE-2026-43198 has been patched. Fixed versions include 6.18.16, 6.19.6 and 7.0. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43198 actively exploited?

CVE-2026-43198 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Race Condition (CWE-362)?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/362.html

CVE-2026-43198

Critical

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.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-11

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.8

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-362

CVE-2026-43198 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.12 and later are affected. Fixed in 6.18.16, 6.19.6, 7.0 and their respective stable series.

Affected from

≥ 2.6.12

Fixed in

✓ 6.18.16 6.18.x ✓ 6.19.6 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-43198 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b
Patch
Kernel patch commit
https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae
Patch
Kernel patch commit
https://git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1fadd
Patch

Details

CVE ID CVE-2026-43198

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-11

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43198?

CVE-2026-43198 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 2.6.12 onward and has been patched in 6.18.16, 6.19.6 and 7.0. CVE-2026-43198 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43198?

CVE-2026-43198 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-43198?

Yes — CVE-2026-43198 has been patched. Fixed versions include 6.18.16, 6.19.6 and 7.0. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43198 actively exploited?

No — CVE-2026-43198 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Race Condition (CWE-362)?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. View CWE-362 on MITRE CWE →