Description
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).
Published: 2026-10-20
Score: 4.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Immediate Patch
AI Analysis

Impact

A vulnerability in the Optimizer component of Oracle MySQL Server and MySQL Cluster allows an attacker who already has high‑privileged credentials and network access via multiple protocols to trigger a hang or repeated crash of the database service, resulting in a denial‑of‑service. The CVSS 3.1 base score is 4.9, reflecting a moderate severity with availability impact only. No information indicates that the flaw could lead to data loss, tampering or remote code execution.

Affected Systems

This flaw affects Oracle MySQL Server versions 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, and 26.7.0 to 26.7.1, as well as Oracle MySQL Cluster versions 8.0.0 to 8.0.49, 8.4.0 to 8.4.12, 9.7.0 to 9.7.3, and 26.7.0 to 26.7.1. The impact is confinement to the affected MySQL installations – other Oracle products are not mentioned as vulnerable.

Risk and Exploitability

The CVSS base score of 4.9 signifies a moderate level of severity focused solely on availability. An EPSS score of less than 1% indicates a very low probability that the vulnerability will be exploited in the wild, and it is not listed in the CISA KEV catalog. However, an attacker who already possesses high‑privileged credentials on the network and can reach the MySQL service via any of the supported protocols could exploit the optimizer flaw to cause the database server or cluster to hang or crash repeatedly, resulting in a denial‑of‑service for applications depending on the database. The vulnerability does not provide a path for privilege escalation or data tampering beyond the service interruption.

Generated by OpenCVE AI on October 23, 2026 at 05:33 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the Oracle MySQL security patch that fixes the optimizer‑related denial‑of‑service flaw for all affected Server and Cluster versions listed above.
  • Restrict network exposure of MySQL Server and Cluster instances by permitting connections only from trusted IP ranges or through a bastion host, thereby limiting the ability of a high‑privileged attacker to reach the vulnerable component.
  • Monitor MySQL logs for abnormal hang or frequent crash events and review resource limits or restart policies to recover from service outages caused by this vulnerability.

Generated by OpenCVE AI on October 23, 2026 at 05:33 UTC.

Tracking

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Advisories

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History

Fri, 23 Oct 2026 02:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-120

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Title Optimizer Component Crash Leading to Denial of Service in Oracle MySQL Server and Cluster mysql: MySQL Server: Denial of service in the Server Optimizer
Weaknesses CWE-400
References
Metrics threat_severity

None

 threat_severity

Moderate

Thu, 22 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-284
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 21 Oct 2026 04:30:00 +0000

Type Values Removed Values Added
Title Optimizer Component Crash Leading to Denial of Service in Oracle MySQL Server and Cluster
Weaknesses CWE-120

Tue, 20 Oct 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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).
First Time appeared Oracle
Oracle mysql Cluster
Oracle mysql Server
CPEs cpe:2.3:a:oracle:mysql_cluster:*:*:*:*:*:*:*:*
cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*
Vendors & Products Oracle
Oracle mysql Cluster
Oracle mysql Server
References
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

Subscriptions

Oracle Mysql Cluster Mysql Server
cve-icon MITRE

Status: PUBLISHED

Assigner: oracle

Published:

Updated: 2026-10-22T17:45:31.641Z

Reserved: 2026-09-28T15:40:09.502Z

Link: CVE-2026-101731

cve-icon Vulnrichment

Updated: 2026-10-22T17:43:40.575Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-20T22:18:27.960

Modified: 2026-10-28T20:22:04.557

Link: CVE-2026-101731

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-20T21:22:34Z

Links: CVE-2026-101731 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T05:45:12Z

Weaknesses
  • CWE-284

    Improper Access Control

  • CWE-400

    Uncontrolled Resource Consumption