---
id: CVE-2026-89650
title: >-
  kernel: ceph: bound num_export_targets array for mds info v2/v3
  (CVE-2026-89650)
summary: >-
  A flaw was found in the Linux kernel's Ceph client. A malicious or compromised
  Ceph monitor, or an on-path attacker, can send a specially crafted Metadata
  Server (MDS) map. This map, with an oversized num_export_targets field and a
  per-MDS…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-125
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T17:38:55+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89650.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89650.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89650'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532105'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89650'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89650'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89650.mbox
  - url: 'https://git.kernel.org/stable/c/0c4bcc3ba7291d383b82ce1c2fe324f69a42da2d'
  - url: 'https://git.kernel.org/stable/c/55a06b32438c222765138727d0a8164b103e8f0d'
  - url: 'https://git.kernel.org/stable/c/eb3e1a1cb1634c76d59c5a9cb1a026fc69d40911'
  - url: 'https://git.kernel.org/stable/c/3bf7dba8dba9a05774b846affec61a3624ddba38'
  - url: 'https://git.kernel.org/stable/c/58c2d3e954c13694ef6e820a5e9456461bb9e7df'
  - url: 'https://git.kernel.org/stable/c/332c444f4dc6fa1e8b8637c9e82d29e97f768656'
  - url: 'https://git.kernel.org/stable/c/a3eb169ee297aa99670ba927c659990bd1e453f3'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00509
epssPercentile: 0.42467
scores:
  vendor: 7
  cna: 9.1
ingestedAt: '2026-09-14T15:23:07.450Z'
---

## Overview

A flaw was found in the Linux kernel's Ceph client. A malicious or compromised Ceph monitor, or an on-path attacker, can send a specially crafted Metadata Server (MDS) map. This map, with an oversized num_export_targets field and a per-MDS info version of 2 or 3, can trigger an out-of-bounds read in the client kernel. This could lead to system instability or a denial of service.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89650.json)

**kernel: ceph: bound num_export_targets array for mds info v2/v3** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-18.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

Not affected:

- Red Hat Enterprise Linux 6

## Remediation

Affected