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: Apply Update
AI Analysis

Impact

The flaw resides in the optimizer component of Oracle MySQL Server and MySQL Cluster. An attacker who can obtain high‑level privileges and reach the database over the network can send specially crafted requests that force the optimizer to enter an invalid state, leading to a hang or an immediate crash of the server. The consequence is a complete denial of service, forcing a restart of the affected database instance. The weakness is characterized by the uncontrolled resource consumption and improper access control reflected in CWE‑284 and CWE‑835.

Affected Systems

Oracle MySQL Server and MySQL Cluster are impacted. The vulnerability exists in 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, as well as in 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. It specifically targets the optimizer that processes query input from the network.

Risk and Exploitability

The CVSS base score of 4.9 classifies the issue as medium severity for availability impact. The EPSS score is below 1 %, indicating a low likelihood of exploitation. The vulnerability is not listed in CISA KEV. Attack execution requires an attacker to possess high‑privilege accounts on the database or to elevate privileges first, together with network connectivity to the MySQL instance. No user interaction is required, so environments where the database is exposed to untrusted traffic face a moderate risk of experiencing a denial of service.

Generated by OpenCVE AI on October 23, 2026 at 06:37 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Check for and apply any available Oracle patches that address MySQL vulnerabilities, as no official patch is listed in the CVE data.
  • Restrict high‑level privileges on remote connections by revoking SUPER or other privileged roles from accounts exposed to the network, thereby limiting the attacker’s ability to trigger the flaw.
  • Configure MySQL resource limits—such as max_heap_table_size, tmp_table_size, connect_timeout, and max_allowed_packet—to dampen potential runaway processes and memory exhaustion.
  • Implement firewall or network segmentation rules to restrict inbound connections to the MySQL server to trusted hosts, reducing exposure; note that no official workaround is provided, so isolation can mitigate risk until a patch is available.

Generated by OpenCVE AI on October 23, 2026 at 06:37 UTC.

Tracking

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Advisories

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History

Fri, 23 Oct 2026 02:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-400

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

Type Values Removed Values Added
Title Denial of Service in MySQL Server Optimizer Leading to Crashes mysql: mysql: Denial of Service in Server Optimizer
Weaknesses CWE-835
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 03:30:00 +0000

Type Values Removed Values Added
Title Denial of Service in MySQL Server Optimizer Leading to Crashes
Weaknesses CWE-20
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 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: 2026-10-22T17:19:46.241Z

Reserved: 2026-09-28T15:40:09.507Z

Link: CVE-2026-101801

cve-icon Vulnrichment

Updated: 2026-10-22T17:02:41.446Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-20T22:18:35.963

Modified: 2026-10-22T18:17:24.567

Link: CVE-2026-101801

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-20T21:23:01Z

Links: CVE-2026-101801 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T06:45:07Z

Weaknesses
  • CWE-284

    Improper Access Control

  • CWE-835

    Loop with Unreachable Exit Condition ('Infinite Loop')