---
id: CVE-2026-68433
title: 'libceph: bound get_version reply decode to front len'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  libceph: bound get_version reply decode to front len

  handle_get_version_reply() uses msg->front_alloc_len as the decode
  boundary for MON_GET_VERSION_REPLY.  That is th…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    1307028f082756bf453e1889aee9983d30643a4b
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    72a35070fcefa229b1b031aa7482ad3788e18f07
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    340e0386aa39da181015bee38f309018c335ce16
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    d60de8253c85a02d0e6194b0735e7a562981a04c
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    4e7ebfaa0d14cf50e44041bfde38070d6dbc019f
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    0d934c934ec746d53fc7e4f53239792647bbae63
  - >-
    Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 <
    d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0
  - Linux 3.16
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T15:48:55.526707Z'
published: '2026-08-12'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:53:13.520Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68433'
references:
  - url: 'https://git.kernel.org/stable/c/1307028f082756bf453e1889aee9983d30643a4b'
  - url: 'https://git.kernel.org/stable/c/f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e'
  - url: 'https://git.kernel.org/stable/c/72a35070fcefa229b1b031aa7482ad3788e18f07'
  - url: 'https://git.kernel.org/stable/c/340e0386aa39da181015bee38f309018c335ce16'
  - url: 'https://git.kernel.org/stable/c/d60de8253c85a02d0e6194b0735e7a562981a04c'
  - url: 'https://git.kernel.org/stable/c/4e7ebfaa0d14cf50e44041bfde38070d6dbc019f'
  - url: 'https://git.kernel.org/stable/c/0d934c934ec746d53fc7e4f53239792647bbae63'
  - url: 'https://git.kernel.org/stable/c/d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0'
tags:
  - cve.org
epss: 0.00291
epssPercentile: 0.20251
ingestedAt: '2026-10-16T17:24:46.866Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

libceph: bound get_version reply decode to front len

handle_get_version_reply() uses msg->front_alloc_len as the decode
boundary for MON_GET_VERSION_REPLY.  That is the size of the reused
reply buffer, not the number of bytes actually received.

A truncated reply can therefore pass ceph_decode_need() and decode the
second u64 from stale tail bytes left in the buffer by an earlier
message, causing an uninitialized memory read.

Use msg->front.iov_len as the receive-side decode boundary, matching
other libceph reply handlers and limiting decoding to the bytes that
were actually read from the wire.

## Affected

- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < 1307028f082756bf453e1889aee9983d30643a4b`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < 72a35070fcefa229b1b031aa7482ad3788e18f07`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < 340e0386aa39da181015bee38f309018c335ce16`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < d60de8253c85a02d0e6194b0735e7a562981a04c`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < 4e7ebfaa0d14cf50e44041bfde38070d6dbc019f`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < 0d934c934ec746d53fc7e4f53239792647bbae63`
- `Linux >= 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 < d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0`
- `Linux 3.16`

## Remediation

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