CVE-2026-21998
Denial of Service in Oracle MySQL Server Optimizer Component
Publication date: 2026-04-21
Last updated on: 2026-04-23
Assigner: Oracle
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| oracle | mysql_server | From 8.0.0 (inc) to 8.0.45 (inc) |
| oracle | mysql_server | From 8.4.0 (inc) to 8.4.8 (inc) |
| oracle | mysql_server | From 9.0.0 (inc) to 9.6.0 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-400 | The product does not properly control the allocation and maintenance of a limited resource. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the MySQL Server product of Oracle MySQL, specifically in the Server Optimizer component. It affects supported versions 8.0.0 to 8.0.45, 8.4.0 to 8.4.8, and 9.0.0 to 9.6.0.
The vulnerability is easily exploitable by a high privileged attacker who has network access through multiple protocols. Exploiting this vulnerability allows the attacker to compromise the MySQL Server.
Successful exploitation can cause the MySQL Server to hang or crash repeatedly, resulting in a complete denial of service (DoS).
How can this vulnerability impact me? :
The main impact of this vulnerability is on the availability of the MySQL Server.
An attacker with high privileges and network access can exploit this vulnerability to cause the server to hang or crash repeatedly, leading to a complete denial of service.
This means that legitimate users may be unable to access the database services, potentially disrupting business operations that depend on MySQL Server.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows a high privileged attacker to cause a denial of service (DoS) by crashing the MySQL Server, impacting availability.
However, there is no information provided about any impact on confidentiality or integrity of data, which are critical for compliance with standards like GDPR or HIPAA.
Therefore, based on the available information, this vulnerability primarily affects availability but does not directly indicate non-compliance with data protection regulations.