What is CVE-2026-43215?

CVE-2026-43215 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10, classified as a Improper Locking flaw (CWE-667), affecting Linux kernel versions from 6.0 onward and patched in 6.6.128, 6.12.75, 6.18.16 and others. CVE-2026-43215 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43215?

CVE-2026-43215 has a CVSS score of 8.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-43215?

Yes, CVE-2026-43215 has been patched. Fixed versions include 6.6.128, 6.12.75, 6.18.16 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43215 actively exploited?

CVE-2026-43215 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Improper Locking (CWE-667)?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/667.html

CVE-2026-43215

High

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix locking usage for tcon fields We used to use the cifs_tcp_ses_lock to protect a lot of objects that are not just the server, ses or tcon lists. We later introduced srv_lock, ses_lock and tc_lock to protect fields within the corresponding structs. This was done to provide a more granular protection and avoid unnecessary serialization. There were still a couple of uses of cifs_tcp_ses_lock to provide tcon fields. In this patch, I've replaced them with tc_lock.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-11

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

8.8

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-667

CVE-2026-43215 is a Improper Locking vulnerability

What is Improper Locking?

The product does not properly acquire or release a lock, which can lead to unexpected behaviour. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.0 and later are affected. Fixed in 6.6.128, 6.12.75, 6.18.16, 6.19.6, 7.0 and their respective stable series.

Affected from

≥ 6.0

Fixed in

✓ 6.6.128 6.6.x ✓ 6.12.75 6.12.x ✓ 6.18.16 6.18.x ✓ 6.19.6 6.19.x ✓ 7.0

References

5 total

Kernel Git
https://git.kernel.org/stable/c/3969db6b22e3d90d8c5f22ac1a7fe0350a94c136

Patch
Kernel Git
https://git.kernel.org/stable/c/601dd3b79769b38d30b693c40afdb2a4b7edf9d0

Patch
Kernel Git
https://git.kernel.org/stable/c/8c59eeeeffa1524ef57e173a89a1a3ff539888d5

Patch
Kernel Git
https://git.kernel.org/stable/c/953953abb66e52c224057ab91e404284fefeab62

Patch
Kernel Git
https://git.kernel.org/stable/c/96c4af418586ee9a6aab61738644366426e05316

Patch

Details

CVE ID CVE-2026-43215

Severity High

CVSS score 8.8 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-11

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43215?

CVE-2026-43215 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 , classified as an Improper Locking flaw (CWE-667) . It affects Linux kernel versions from 6.0 onward and has been patched in 6.6.128, 6.12.75, 6.18.16 and others. CVE-2026-43215 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43215?

CVE-2026-43215 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-43215?

Yes. CVE-2026-43215 has been patched. Fixed versions include 6.6.128, 6.12.75, 6.18.16 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43215 actively exploited?

No. CVE-2026-43215 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.