---
id: CVE-2026-43406
title: 'libceph: prevent potential out-of-bounds reads in process_message_header()'
summary: |-
  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 segm…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    76ccf21a12c5f6d6790bc32c7da82446d877b2f4
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    75582aaa580c11aed4c7731cad6b068b700e7efb
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    50156622eb0888e62541d715a98584480a1bc7cb
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    dbd857a9e1e33ea71eaf3e211877027e533770d1
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    69fe5af33fa3806f398d21c081d73c66e5523bc2
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    035867ae6f18df0aeedb2a57a5b74091bd4e3fe8
  - >-
    Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 <
    69fb5d91bba44ecf7eb80530b85fa4fb028921d5
  - Linux 5.11
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T15:17:09.082944Z'
published: '2026-05-08'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:41.086Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43406'
references:
  - url: 'https://git.kernel.org/stable/c/76ccf21a12c5f6d6790bc32c7da82446d877b2f4'
  - url: 'https://git.kernel.org/stable/c/75582aaa580c11aed4c7731cad6b068b700e7efb'
  - url: 'https://git.kernel.org/stable/c/50156622eb0888e62541d715a98584480a1bc7cb'
  - url: 'https://git.kernel.org/stable/c/dbd857a9e1e33ea71eaf3e211877027e533770d1'
  - url: 'https://git.kernel.org/stable/c/69fe5af33fa3806f398d21c081d73c66e5523bc2'
  - url: 'https://git.kernel.org/stable/c/035867ae6f18df0aeedb2a57a5b74091bd4e3fe8'
  - url: 'https://git.kernel.org/stable/c/69fb5d91bba44ecf7eb80530b85fa4fb028921d5'
tags:
  - cve.org
epss: 0.00718
epssPercentile: 0.52913
ingestedAt: '2026-10-16T17:24:46.695Z'
---

## Overview

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.

## Affected

- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 76ccf21a12c5f6d6790bc32c7da82446d877b2f4`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 75582aaa580c11aed4c7731cad6b068b700e7efb`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 50156622eb0888e62541d715a98584480a1bc7cb`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < dbd857a9e1e33ea71eaf3e211877027e533770d1`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 69fe5af33fa3806f398d21c081d73c66e5523bc2`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 035867ae6f18df0aeedb2a57a5b74091bd4e3fe8`
- `Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 69fb5d91bba44ecf7eb80530b85fa4fb028921d5`
- `Linux 5.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.