A vulnerability in the Oracle MySQL Server component 'Optimizer' affects multiple versions including 8.0.39 and prior, 8.4.2 and prior, and 9.0.1 and prior. This flaw allows a high-privileged attacker with network access to cause a denial of service (DoS) by hanging or crashing the MySQL Server. The vulnerability has a CVSS 3.1 base score of 4.9, indicating a medium severity impact focused on availability.