CVE-2026-43406

Critical

In the Linux kernel, the following vulnerability has been resolved: libceph: prevent potential out-of-bounds reads in process_message_header() If the message frame is (maliciously) corrupted in a way that the length of the control segment ends up being less than the size of the message header or a different frame is made to look like a message frame, out-of-bounds reads may ensue in process_message_header(). Perform an explicit bounds check before decoding the message header.

Package Linux Kernel
Published 2026-05-08
Last modified 2026-05-21
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

9.1

out of 10
Critical
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Weakness type

CWE-125

CVE-2026-43406 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 5.11 and later are affected. Fixed in 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
≥ 5.11
Fixed in
✓ 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

The following references provide additional information about CVE-2026-43406 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-43406?

    CVE-2026-43406 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 5.11 onward and has been patched in 5.15.203, 6.1.167, 6.6.130 and others. CVE-2026-43406 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-43406?

    CVE-2026-43406 has a CVSS score of 9.1 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:N/A:H .

  • Is there a patch available for CVE-2026-43406?

    Yes — CVE-2026-43406 has been patched. Fixed versions include 5.15.203, 6.1.167, 6.6.130 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-43406 actively exploited?

    No — CVE-2026-43406 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (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. View CWE-125 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST