Secuno
ENNL
Book demo

CVE-2026-43198

Linux Kernel race condition

9.8 CRITICALEPSS 0.30%
  1. Published6 May 2026

Description

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 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 2.6.12.1 < 6.18.16 · ≥ 6.19 < 6.19.6 · 2.6.12 · 7.0

Remediation

Fixed in
Linux Kernel≥ 6.18.16

References

and 15 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1065008.5
Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1,…
CVE-2026-1064268.3
Race condition in Fonts in Google Chrome prior to 155.0.8059.39 allowed a remote…
CVE-2026-1063778.3
Race condition in Fonts in Google Chrome prior to 155.0.8059.39 allowed a remote…
CVE-2026-1062558.8
Race condition in V8 in Google Chrome prior to 155.0.8059.39 allowed a remote attacker…
CVE-2026-1062388.3
Race condition in Fonts in Google Chrome prior to 155.0.8059.39 allowed a remote…
CVE-2026-1062018.8
Race condition in V8 in Google Chrome prior to 155.0.8059.39 allowed a remote attacker…

Frequently asked

Is CVE-2026-43198 being actively exploited?

CVE-2026-43198 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.30%.

How severe is CVE-2026-43198?

CVE-2026-43198 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.30% probability of exploitation.

Which products are affected by CVE-2026-43198?

Affected products include Linux Kernel.

How do I fix CVE-2026-43198?

Upgrade affected software to a fixed version, for example Linux Kernel 6.18.16 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-43198 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.