CVE-2025-21494 Denial of service in MySQL Server

Medium 4.1 Published 21 Jan 2025 Updated 3 Nov 2025

A high-privileged attacker with local access can cause a complete denial of service in MySQL Server by triggering a hang or crash.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2025-21494?

CVE-2025-21494 is a medium-severity denial of service vulnerability in Oracle Mysql Server, published on 21 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Security: Privileges). Supported versions that are affected are 8.0.39 and prior, 8.4.2 and prior and 9.0.1 and prior. Difficult to exploit vulnerability allows high privileged attacker with logon to the infrastructure where MySQL Server executes to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.1 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H).

Weakness: CWE-770

Which versions are affected by CVE-2025-21494?

It affects 1 product.

Products include Oracle Mysql Server.

How do I fix CVE-2025-21494?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-21494 being exploited?

There is no known exploitation of CVE-2025-21494 in the wild and no public exploit code.

All Oracle Mysql Server vulnerabilities

Sources

Also known as GHSA-7vhr-3h3v-9gqg, UBUNTU-CVE-2025-21494.