What is CVE-2026-21950?

CVE-2026-21950 is a medium-severity vulnerability in Oracle MySQL Server, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-01-20.

How severe is CVE-2026-21950?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Resource exhaustion in Oracle MySQL Server

CVE-2026-21950

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 9.0.0-9.5.0. Easily exploitable vulnerability allows low 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 6.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Vulnerability class: DoS (Denial of Service)

EPSS: 0.003 (24.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Oracle Mysql_server
Oracle Corporation Mysql Server — versions 9.0.0

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

secalert_us@oracle.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21950?: CVE-2026-21950 is a medium-severity vulnerability in Oracle MySQL Server, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-01-20.
How severe is CVE-2026-21950?: Medium severity. CVSS v3 base score is 6.5 out of 10.