What is CVE-2026-43384?

CVE-2026-43384 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 6.7 onward and patched in 6.12.78, 6.18.19, 6.19.9 and others. CVE-2026-43384 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43384?

CVE-2026-43384 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-2026-43384?

Yes, CVE-2026-43384 has been patched. Fixed versions include 6.12.78, 6.18.19, 6.19.9 and others. If you are running Linux kernel 6.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43384 actively exploited?

CVE-2026-43384 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43384

Critical

In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

Package Linux Kernel

Published 2026-05-08

Last modified 2026-05-26

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

Affected versions

Linux kernel versions 6.7 and later are affected. Fixed in 6.12.78, 6.18.19, 6.19.9, 7.0 and their respective stable series.

Affected from

≥ 6.7

Fixed in

✓ 6.12.78 6.12.x ✓ 6.18.19 6.18.x ✓ 6.19.9 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-43384 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/080b0e210088296dd50d6637c06c1db14246adfe
Patch
Kernel patch commit
https://git.kernel.org/stable/c/67edfec516d30d3e62925c397be4a1e5185802fc
Patch
Kernel patch commit
https://git.kernel.org/stable/c/8be6ed64966da48b6c4726918f106c18742a5125
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2026-43384

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-05-08

Modified 2026-05-26

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43384?

CVE-2026-43384 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 6.7 onward and has been patched in 6.12.78, 6.18.19, 6.19.9 and others. CVE-2026-43384 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43384?

CVE-2026-43384 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-2026-43384?

Yes — CVE-2026-43384 has been patched. Fixed versions include 6.12.78, 6.18.19, 6.19.9 and others. If you are running Linux kernel 6.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43384 actively exploited?

No — CVE-2026-43384 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.