---
title: "CVE-2026-89650: Linux Kernel Ceph - Out-of-Bounds Read"
description: "Linux kernel Ceph component (info_v 2 and 3) contains an out-of-bounds read caused by missing bounds check on num_export_targets in ceph_mdsmap_decode(), letting malicious or compromised Ceph monitors trigger kernel memory read, exploit requires a malicious or compromised Ceph monitor or on-path attacker on unsigned messenger session."
url: https://panop.io/threat-heartbeat/CVE-2026-89650/
---

# CVE-2026-89650 Linux Kernel Ceph - Out-of-Bounds Read

Linux kernel Ceph component (info\_v 2 and 3) contains an out-of-bounds read caused by missing bounds check on num\_export\_targets in ceph\_mdsmap\_decode(), letting malicious or compromised Ceph monitors trigger kernel memory read, exploit requires a malicious or compromised Ceph monitor or on-path attacker on unsigned messenger session.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

EPSS

0.50% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89650)

## Details

Type

Out-of-Bounds Read

Impact

Denial Of Service

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for ceph\_mdsmap\_decode bounds checking.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89650](https://nvd.nist.gov/vuln/detail/CVE-2026-89650)
- [https://git.kernel.org/stable/c/332c444f4dc6fa1e8b8637c9e82d29e97f768656](https://git.kernel.org/stable/c/332c444f4dc6fa1e8b8637c9e82d29e97f768656)
- [https://git.kernel.org/stable/c/3bf7dba8dba9a05774b846affec61a3624ddba38](https://git.kernel.org/stable/c/3bf7dba8dba9a05774b846affec61a3624ddba38)
- [https://git.kernel.org/stable/c/58c2d3e954c13694ef6e820a5e9456461bb9e7df](https://git.kernel.org/stable/c/58c2d3e954c13694ef6e820a5e9456461bb9e7df)
- [https://git.kernel.org/stable/c/a3eb169ee297aa99670ba927c659990bd1e453f3](https://git.kernel.org/stable/c/a3eb169ee297aa99670ba927c659990bd1e453f3)
- [https://git.kernel.org/stable/c/0c4bcc3ba7291d383b82ce1c2fe324f69a42da2d](https://git.kernel.org/stable/c/0c4bcc3ba7291d383b82ce1c2fe324f69a42da2d)
- [https://git.kernel.org/stable/c/55a06b32438c222765138727d0a8164b103e8f0d](https://git.kernel.org/stable/c/55a06b32438c222765138727d0a8164b103e8f0d)
- [https://git.kernel.org/stable/c/eb3e1a1cb1634c76d59c5a9cb1a026fc69d40911](https://git.kernel.org/stable/c/eb3e1a1cb1634c76d59c5a9cb1a026fc69d40911)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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