---
id: CVE-2026-101789
title: 'mysql: mysql: Denial of Service via the Optimizer component (CVE-2026-101789)'
summary: >-
  A flaw was found in the MySQL Optimizer component. An authenticated remote
  attacker with low privileges can exploit this vulnerability over the network
  to cause a Denial of Service (DoS). Successful exploitation allows the
  attacker to hang…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-400
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
  - enterprise_linux 9
published: '2026-10-20'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T22:20:09+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-101789.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-101789.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-101789'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2557265'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-101789'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101789'
  - url: 'https://www.oracle.com/security-alerts/cpuoct2026.html'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00353
epssPercentile: 0.28744
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-22T17:02:26.761746Z'
ingestedAt: '2026-10-20T22:23:33.920Z'
---

## Overview

A flaw was found in the MySQL Optimizer component. An authenticated remote attacker with low privileges can exploit this vulnerability over the network to cause a Denial of Service (DoS). Successful exploitation allows the attacker to hang or repeatedly crash the server, disrupting database operations for legitimate users.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-101789.json)

**mysql: mysql: Denial of Service via the Optimizer component** — rated Moderate by Red Hat. Released 2026-10-20, updated 2026-10-22.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9

Not affected:

- Red Hat Enterprise Linux 6
- Red Hat Hardened Images

## Remediation

Affected