What is CVE-2026-43178?

CVE-2026-43178 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 6.12.70 onward and patched in 6.12.75, 6.18.16, 6.19.6 and others. CVE-2026-43178 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43178?

CVE-2026-43178 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-43178?

Yes, CVE-2026-43178 has been patched. Fixed versions include 6.12.75, 6.18.16, 6.19.6 and others. If you are running Linux kernel 6.12.70 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43178 actively exploited?

CVE-2026-43178 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-43178

High

In the Linux kernel, the following vulnerability has been resolved: procfs: fix possible double mmput() in do_procmap_query() When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf.

Package Linux Kernel

Published 2026-05-06

Last modified 2026-05-12

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-415

CVE-2026-43178 is classified as CWE-415

See CWE-415 on MITRE CWE for full details on this weakness type.

Affected versions

Linux kernel versions 6.12.70, 6.18.10, 6.19 and later are affected. Fixed in 6.12.75, 6.18.16, 6.19.6, 7.0 and their respective stable series.

Affected from

≥ 6.12.70 ≥ 6.18.10 ≥ 6.19

Fixed in

✓ 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-2026-43178 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/61dc9f776705d6db6847c101b98fa4f0e9eb6fa3
Patch
Kernel patch commit
https://git.kernel.org/stable/c/8adaff87db143583e08eec4f4e7788f1ef8af94d
Patch
Kernel patch commit
https://git.kernel.org/stable/c/90f5e87c9b75833b9ef3a4415b92c0247f28ab2f
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2026-43178

Severity High

CVSS score 7.8 / 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-2026-43178?

CVE-2026-43178 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 6.12.70 onward and has been patched in 6.12.75, 6.18.16, 6.19.6 and others. CVE-2026-43178 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43178?

CVE-2026-43178 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-43178?

Yes — CVE-2026-43178 has been patched. Fixed versions include 6.12.75, 6.18.16, 6.19.6 and others. If you are running Linux kernel 6.12.70 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43178 actively exploited?

No — CVE-2026-43178 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.