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).

A flaw was found in the query optimizer component of MySQL Server and MySQL Cluster. An authenticated attacker with high privileges and network access can exploit this vulnerability to cause a Denial of Service (DoS). Successful exploitation allows the attacker to hang or repeatedly crash the database server.

This vulnerability is rated as Moderate for Red Hat Enterprise Linux because exploitation requires elevated administrative privileges, significantly constraining the threat to authenticated users with high-level database permissions. While triggering the optimizer flaw can lead to service unavailability by halting or crashing the database daemon, it does not compromise data confidentiality or integrity. Standard deployments that strictly segregate administrative credentials and limit privileged database operations substantially diminish the operational risk of this defect. Red Hat Enterprise Linux 10 Affected mysql8.4 Red Hat Enterprise Linux 6 Not affected mysql Red Hat Enterprise Linux 9 Affected mysql Red Hat Hardened Images Not affected mariadb10.11 Red Hat Hardened Images Not affected mariadb11.8 https://www.cve.org/CVERecord?id=CVE-2026-101784 https://nvd.nist.gov/vuln/detail/CVE-2026-101784 https://www.oracle.com/security-alerts/cpuoct2026.html