CVE-2024-21171 is a vulnerability in the Oracle MySQL Server component 'Optimizer' affecting versions 8.0.37 and prior, and 8.4.0 and prior. It allows a low-privileged attacker with network access to cause a denial of service by hanging or crashing the MySQL Server. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity impact focused on availability.