What is CVE-2026-43399?

CVE-2026-43399 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.16 onward and patched in 6.18.19, 6.19.9 and 7.0. CVE-2026-43399 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43399?

CVE-2026-43399 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-43399?

Yes, CVE-2026-43399 has been patched. Fixed versions include 6.18.19, 6.19.9 and 7.0. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43399 actively exploited?

CVE-2026-43399 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43399

Medium

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/userq: Fix reference leak in amdgpu_userq_wait_ioctl Drop reference to syncobj and timeline fence when aborting the ioctl due output array being too small. (cherry picked from commit 68951e9c3e6bb22396bc42ef2359751c8315dd27)

Package Linux Kernel

Published 2026-05-08

Last modified 2026-05-21

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.16 and later are affected. Fixed in 6.18.19, 6.19.9, 7.0 and their respective stable series.

Affected from

≥ 6.16

Fixed in

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

References

The following references provide additional information about CVE-2026-43399 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/49abfa812617a7f2d0132c70d23ac98b389c6ec1
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5409247d41f372bec5b141ef599f2d9f5e81b746
Patch
Kernel patch commit
https://git.kernel.org/stable/c/762f47e2b824383d5be65eee2c40a1269b7d50c8
Patch

Details

CVE ID CVE-2026-43399

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-08

Modified 2026-05-21

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43399?

CVE-2026-43399 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.16 onward and has been patched in 6.18.19, 6.19.9 and 7.0. CVE-2026-43399 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43399?

CVE-2026-43399 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-43399?

Yes — CVE-2026-43399 has been patched. Fixed versions include 6.18.19, 6.19.9 and 7.0. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43399 actively exploited?

No — CVE-2026-43399 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.