# CVE-2026-21998

> Vulnerability · severity: **MEDIUM** (CVSS 4.9).

## Description

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer).  Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and  9.0.0-9.6.0. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols 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 4.9 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

## Key facts

- **CVE ID:** CVE-2026-21998
- **Published:** 2026-04-21
- **CVSS severity:** MEDIUM
- **CVSS base score:** 4.9
- **CWE codes:** CWE-400

## Affected products

- `oracle:mysql_server`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21998

## Citation

> AI Analytics. CVE-2026-21998. Retrieved 2026-05-20 from https://api.ai-analytics.org/cve/CVE-2026-21998. Derived from NIST NVD. Licensed CC0.

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