---
id: "CVE-2026-101732"
kind: "vulnerability"
aliases: ["CVE-2026-101732"]
title: "MySQL Server optimizer flaw lets a privileged user crash the database"
severity: "medium"
cvss: 4.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["database", "mysql", "mysql-cluster", "package", "self-hosted"]
not_affected_if: ["unaffected-version"]
published_at: "2026-10-20T22:18:28+00:00"
first_seen_at: "2026-10-23T21:57:23+00:00"
updated_at: "2026-10-25T04:31:22+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101732", "first_seen_at": "2026-10-23T21:57:23+00:00"}]
---

# MySQL Server optimizer flaw lets a privileged user crash the database

A flaw in the MySQL Server optimizer lets a highly privileged attacker over the network cause a hang or repeatable crash of MySQL Server and MySQL Cluster. The sources describe only availability impact, with no data read or code execution.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `SELECT @@version;` on each MySQL Server and MySQL Cluster node and compare against the affected ranges: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1 for MySQL Server, and 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1 for MySQL Cluster.

## Fix

- Upgrade MySQL Server and MySQL Cluster to a release outside the affected ranges, as published in Oracle's April 2026 Critical Patch Update (exact fixed version unknown from the sources).

## Timeline

- 2026-10-23T21:57:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-101732

## From the sources

Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Optimizer).  Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and  26.7.0-26.7.1. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server, MySQL Cluster. CVSS 3.1 Base Score 4.9 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

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