What is CVE-2026-43400?

CVE-2026-43400 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-2026-43400 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43400?

CVE-2026-43400 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-2026-43400?

Yes, CVE-2026-43400 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-2026-43400 actively exploited?

CVE-2026-43400 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43400

Medium

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: add upper bound check on user inputs in signal ioctl Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and could be exploited. So check these input value against AMDGPU_USERQ_MAX_HANDLES which is big enough value for genuine use cases and could potentially avoid OOM. (cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)

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-2026-43400 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/46630d966b99b0fc6cb01fef4110587f3375a0c0
Patch
Kernel patch commit
https://git.kernel.org/stable/c/6fff5204d8aa26b1be50b6427f833bd3e8899c4f
Patch
Kernel patch commit
https://git.kernel.org/stable/c/ea78f8c68f4f6211c557df49174c54d167821962
Patch

Details

CVE ID CVE-2026-43400

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-2026-43400?

CVE-2026-43400 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-2026-43400 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43400?

CVE-2026-43400 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-2026-43400?

Yes — CVE-2026-43400 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-2026-43400 actively exploited?

No — CVE-2026-43400 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.