What is CVE-2025-40343?

CVE-2025-40343 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 4.8 onward and patched in 5.15.197, 6.1.159, 6.6.117 and others. CVE-2025-40343 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-40343?

CVE-2025-40343 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-2025-40343?

Yes, CVE-2025-40343 has been patched. Fixed versions include 5.15.197, 6.1.159, 6.6.117 and others. If you are running Linux kernel 4.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-40343 actively exploited?

CVE-2025-40343 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-40343

Critical

In the Linux kernel, the following vulnerability has been resolved: nvmet-fc: avoid scheduling association deletion twice When forcefully shutting down a port via the configfs interface, nvmet_port_subsys_drop_link() first calls nvmet_port_del_ctrls() and then nvmet_disable_port(). Both functions will eventually schedule all remaining associations for deletion. The current implementation checks whether an association is about to be removed, but only after the work item has already been scheduled. As a result, it is possible for the first scheduled work item to free all resources, and then for the same work item to be scheduled again for deletion. Because the association list is an RCU list, it is not possible to take a lock and remove the list entry directly, so it cannot be looked up again. Instead, a flag (terminating) must be used to determine whether the association is already in the process of being deleted.

Package Linux Kernel

Published 2025-12-09

Last modified 2026-07-30

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 4.8 and later are affected. Fixed in 5.15.197, 6.1.159, 6.6.117, 6.12.58, 6.17.8, 6.18 and their respective stable series.

Affected from

≥ 4.8

Fixed in

✓ 5.15.197 5.15.x ✓ 6.1.159 6.1.x ✓ 6.6.117 6.6.x ✓ 6.12.58 6.12.x ✓ 6.17.8 6.17.x ✓ 6.18

References

6 total

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2025-40343

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2025-12-09

Modified 2026-07-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-40343?

CVE-2025-40343 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 4.8 onward and has been patched in 5.15.197, 6.1.159, 6.6.117 and others. CVE-2025-40343 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-40343?

CVE-2025-40343 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-2025-40343?

Yes. CVE-2025-40343 has been patched. Fixed versions include 5.15.197, 6.1.159, 6.6.117 and others. If you are running Linux kernel 4.8 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-40343 actively exploited?

No. CVE-2025-40343 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.