MySQL Server Vulnerability in Oracle MySQL Server: Optimizer Component
CVE-2026-21949

6.5MEDIUM

Key Information:

Vendor

Oracle
Status
Mysql Server
Vendor
CVE Published:
20 January 2026

What is CVE-2026-21949?

A vulnerability exists in the Oracle MySQL Server's Optimizer component that can be exploited by low-privileged attackers with network access through multiple protocols. This vulnerability allows for the potential to cause MySQL Server to hang or frequently crash, resulting in a Denial of Service (DoS). It affects specific versions from 9.0.0 to 9.5.0, making it critical for organizations using these versions to implement necessary security measures to mitigate risks.

Affected Version(s)

MySQL Server 9.0.0 <= 9.5.0

References

https://www.oracle.com/security-alerts/cpujan2026.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

.