Denial of Service Vulnerability in MySQL Server by Oracle
CVE-2026-34303

6.5MEDIUM

Key Information:

Vendor

Oracle
Status
Mysql Server
Vendor
CVE Published:
21 April 2026

What is CVE-2026-34303?

A vulnerability in the MySQL Server product of Oracle MySQL, specifically in the Optimizer component, allows a low-privileged attacker with network access through multiple protocols to exploit the server. This vulnerability can lead to unauthorized actions that cause a complete denial of service (DoS), resulting in frequent crashes or hangs of the MySQL server, affecting system availability.

Affected Version(s)

MySQL Server 8.0.0 <= 8.0.45

MySQL Server 8.4.0 <= 8.4.8

MySQL Server 9.0.0 <= 9.6.0

References

https://www.oracle.com/security-alerts/cpuapr2026.html
vendor-advisory

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.