What is CVE-2026-43239?

CVE-2026-43239 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10, affecting Linux kernel versions from 5.19 onward and patched in 6.6.128, 6.12.75, 6.18.16 and others. CVE-2026-43239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43239?

CVE-2026-43239 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-2026-43239?

Yes, CVE-2026-43239 has been patched. Fixed versions include 6.6.128, 6.12.75, 6.18.16 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43239 actively exploited?

CVE-2026-43239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43239

High

In the Linux kernel, the following vulnerability has been resolved: smb: client: prevent races in ->query_interfaces() It was possible for two query interface works to be concurrently trying to update the interfaces. Prevent this by checking and updating iface_last_update under iface_lock.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-12

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

Affected versions

Linux kernel versions 5.19 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

≥ 5.19

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

The following references provide additional information about CVE-2026-43239 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/6287eefaf21ec805d42f941bd368018cf397a7f5
Patch
Kernel patch commit
https://git.kernel.org/stable/c/76cc4faba0343c6db945b8dc75425b33d633e1b8
Patch
Kernel patch commit
https://git.kernel.org/stable/c/93e8e3ee165ae4609a1222b516b573837103d2c3
Patch

5 patch commits total View all on NVD

Details

CVE ID CVE-2026-43239

Severity High

CVSS score 8.8 / 10

CVSS version 3.1

Published 2026-05-06

Modified 2026-05-12

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43239?

CVE-2026-43239 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 5.19 onward and has been patched in 6.6.128, 6.12.75, 6.18.16 and others. CVE-2026-43239 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43239?

CVE-2026-43239 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-2026-43239?

Yes — CVE-2026-43239 has been patched. Fixed versions include 6.6.128, 6.12.75, 6.18.16 and others. If you are running Linux kernel 5.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43239 actively exploited?

No — CVE-2026-43239 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.