---
id: "CVE-2026-101608"
kind: "vulnerability"
aliases: ["CVE-2026-101608"]
title: "MySQL Server optimizer flaw lets low-privilege users crash the database"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["database", "mysql", "package", "self-hosted"]
not_affected_if: ["default-config"]
published_at: "2026-10-20T22:18:14+00:00"
first_seen_at: "2026-10-23T21:57:22+00:00"
updated_at: "2026-10-25T03:55:10+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101608", "first_seen_at": "2026-10-23T21:57:22+00:00"}]
---

# MySQL Server optimizer flaw lets low-privilege users crash the database

A flaw in the MySQL Server optimizer can be triggered by a low-privileged user over the network to cause a hang or repeatable crash. The impact is denial of service only, with no confidentiality or integrity loss stated.

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

## How to check

- Run `SELECT VERSION();` on the MySQL server and compare against the affected ranges: 8.4.0 through 8.4.12, 9.7.0 through 9.7.3, 26.7.0 through 26.7.1, and MySQL Cluster 8.0.0 through 8.0.49.

## Fix

- Upgrade MySQL Server 8.4.x to a release after `8.4.12`, 9.7.x to a release after `9.7.3`, and 26.7.x to a release after `26.7.1`.
- Upgrade MySQL Cluster 8.0.x to a release after `8.0.49`, and MySQL Cluster 8.4.x and 9.7.x to the same fixed releases as MySQL Server.

## Timeline

- 2026-10-23T21:57:22+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-101608

## 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 low 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 6.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

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