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 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).
Published: 2026-10-20
Score: 6.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Patch
AI Analysis

Impact

The vulnerability resides in the Optimizer component of Oracle MySQL Server and MySQL Cluster. A low‑privileged attacker who can reach the database over the network can trigger the bug, causing the server to hang or crash repeatedly. The defect leads to an uncontrolled resource state that exhausts internal threads, producing a denial‑of‑service condition. The attack does not compromise data confidentiality or integrity; it only makes the service unavailable to legitimate users.

Affected Systems

Oracle MySQL Server versions 8.4.0 through 8.4.12, 9.7.0 through 9.7.3, and 26.7.0 through 26.7.1 are affected, as are Oracle MySQL Cluster versions 8.0.0 through 8.0.49, 8.4.0 through 8.4.12, 9.7.0 through 9.7.3, and 26.7.0 through 26.7.1. No other releases were mentioned.

Risk and Exploitability

The CVSS 3.1 base score of 6.5 indicates moderate severity, with a high impact on availability. The vector AV:N/AC:L/PR:L indicates that remote attackers with low privilege and network access can exploit the flaw, making exploitation relatively easy. The EPSS score is <1%, suggesting a very low but non‑zero probability of exploitation. The vulnerability is not listed in the CISA KEV catalog, implying that no confirmed or likely exploits have been observed in the wild at the time of disclosure.

Generated by OpenCVE AI on October 23, 2026 at 02:27 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest official Oracle patch for the affected MySQL Server and MySQL Cluster versions.
  • Restrict network access to MySQL services to trusted hosts or internal networks using firewall rules or VPN; disable unnecessary protocols where possible.
  • Monitor database performance and logs for repetitive hang or crash patterns, and enable failover or high‑availability configurations to mitigate service disruption.

Generated by OpenCVE AI on October 23, 2026 at 02:27 UTC.

Tracking

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Advisories

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History

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

Type Values Removed Values Added
Title MySQL Optimizer Denial of Service Vulnerability mysql: mysql: Denial of Service via the Optimizer component
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 MySQL Optimizer Denial of Service Vulnerability
Weaknesses CWE-400

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 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).
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': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/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: 2026-10-22T17:20:58.327Z

Reserved: 2026-09-28T15:40:09.506Z

Link: CVE-2026-101789

cve-icon Vulnrichment

Updated: 2026-10-22T17:02:27.986Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-20T22:18:34.630

Modified: 2026-10-22T18:17:23.600

Link: CVE-2026-101789

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-20T21:22:56Z

Links: CVE-2026-101789 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T02:30:15Z

Weaknesses
  • CWE-284

    Improper Access Control

  • CWE-400

    Uncontrolled Resource Consumption