What is CVE-2026-43427?

CVE-2026-43427 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10, classified as a Out-of-bounds Read flaw (CWE-125), affecting Linux kernel versions from 2.6.26 onward and patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2026-43427 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-43427?

CVE-2026-43427 has a CVSS score of 7.1 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:N/A:H.

Is there a patch available for CVE-2026-43427?

Yes, CVE-2026-43427 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.26 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-43427 actively exploited?

CVE-2026-43427 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2026-43427

High

In the Linux kernel, the following vulnerability has been resolved: usb: class: cdc-wdm: fix reordering issue in read code path Quoting the bug report: Due to compiler optimization or CPU out-of-order execution, the desc->length update can be reordered before the memmove. If this happens, wdm_read() can see the new length and call copy_to_user() on uninitialized memory. This also violates LKMM data race rules [1]. Fix it by using WRITE_ONCE and memory barriers.

Package Linux Kernel

Published 2026-05-08

Last modified 2026-05-20

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.1

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-125

CVE-2026-43427 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.26 and later are affected. Fixed in 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9, 7.0 and their respective stable series.

Affected from

≥ 2.6.26

Fixed in

✓ 5.10.253 5.10.x ✓ 5.15.203 5.15.x ✓ 6.1.167 6.1.x ✓ 6.6.130 6.6.x ✓ 6.12.78 6.12.x ✓ 6.18.19 6.18.x ✓ 6.19.9 6.19.x ✓ 7.0

References

8 total

Kernel Git
https://git.kernel.org/stable/c/170e8daca24da6edb4be82ab01abf44e87af387b

Patch
Kernel Git
https://git.kernel.org/stable/c/276aef0fd2b92f41b920ac891c72cadeee957934

Patch
Kernel Git
https://git.kernel.org/stable/c/4ee3062bf2c9a722afef429826e8607eaf3fc6a0

Patch
Kernel Git
https://git.kernel.org/stable/c/638328ca9c17ae6511ad62198c57bae32ffa3c91

Patch
Kernel Git
https://git.kernel.org/stable/c/67ed312124bb1b61858778ac0b985b48961c862a

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-43427

Severity High

CVSS score 7.1 / 10

CVSS version 3.1

Published 2026-05-08

Modified 2026-05-20

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-43427?

CVE-2026-43427 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 2.6.26 onward and has been patched in 5.10.253, 5.15.203, 6.1.167 and others. CVE-2026-43427 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-43427?

CVE-2026-43427 has a CVSS score of 7.1 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:N/A:H.
Is there a patch available for CVE-2026-43427?

Yes. CVE-2026-43427 has been patched. Fixed versions include 5.10.253, 5.15.203, 6.1.167 and others. If you are running Linux kernel 2.6.26 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-43427 actively exploited?

No. CVE-2026-43427 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.