Description
Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are MySQL Server: 9.7.0-9.7.3; MySQL Cluster: 9.7.0-9.7.3. 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 (Availability)
Action: Patch Now
AI Analysis

Impact

Oracle MySQL Server and MySQL Cluster harbor a flaw in the optimizer component that allows an attacker with low privileges and network connectivity to trigger a hang or crash. This results in a complete denial of service by causing the database server to become unresponsive. The vulnerability is classified as a moderate availability issue and affects both the core server and cluster implementations, enabling an attacker to disrupt database operations without escalating privileges.

Affected Systems

Affected vendors are Oracle Corporation for their MySQL Server and MySQL Cluster products. Vulnerable releases span MySQL Server version 9.7.0 through 9.7.3 and MySQL Cluster version 9.7.0 through 9.7.3. Only these specific releases are impacted; later versions are believed to be unaffected.

Risk and Exploitability

The base CVSS score of 6.5 indicates moderate severity for availability. The EPSS score is below 1%, indicating a very low but non‑zero probability of exploitation, though the threat remains nonetheless. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector is over the network, exploiting one of the multiple supported protocols to send crafted optimizer requests that cause a server crash. A successful exploitation requires only low privileges, making the threat sufficiently attractive to potential adversaries seeking to disrupt services.

Generated by OpenCVE AI on October 23, 2026 at 04:49 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest Oracle patch or upgrade MySQL Server and MySQL Cluster beyond version 9.7.3 to eliminate the optimizer vulnerability.
  • Restrict inbound traffic to MySQL ports (default 3306 and cluster ports) to trusted hosts or IP ranges, reducing the attack surface for low‑privileged adversaries.
  • Configure monitoring and alerting on MySQL error logs and system metrics to detect abrupt crashes or hangs, enabling rapid response to residual or novel exploitation attempts.

Generated by OpenCVE AI on October 23, 2026 at 04:49 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

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

Type Values Removed Values Added
Title Low-Privilege Network Attack Triggers MySQL Server and Cluster Crash mysql: mysql: Denial of Service in Server Optimizer
Weaknesses CWE-835
References
Metrics threat_severity

None

 threat_severity

Moderate

Thu, 22 Oct 2026 11:45:00 +0000

Type Values Removed Values Added
Title Low-Privilege Network Attack Triggers MySQL Server and Cluster Crash

Thu, 22 Oct 2026 10:30:00 +0000

Type Values Removed Values Added
Title Denial of Service via Optimizer in MySQL Server and Cluster
Weaknesses CWE-119
CWE-400

Wed, 21 Oct 2026 19:30:00 +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 01:00:00 +0000

Type Values Removed Values Added
Title Denial of Service via Optimizer in MySQL Server and Cluster
Weaknesses CWE-119
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: 9.7.0-9.7.3; MySQL Cluster: 9.7.0-9.7.3. 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: 2026-10-21T18:37:33.559Z

Reserved: 2026-09-28T15:40:09.495Z

Link: CVE-2026-101620

cve-icon Vulnrichment

Updated: 2026-10-21T18:19:23.353Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-20T22:18:15.913

Modified: 2026-10-21T19:16:50.437

Link: CVE-2026-101620

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-20T21:21:56Z

Links: CVE-2026-101620 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T05:00:15Z

Weaknesses
  • CWE-284

    Improper Access Control

  • CWE-835

    Loop with Unreachable Exit Condition ('Infinite Loop')