CVE-2026-34276: Medium severity Oracle MySQL Server (Group Replication Plugin) vulnerability
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Group Replication Plugin). 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 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).
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Remove
Remove
mysql/Group Replication Pluginfrom your environment.If the Group Replication Plugin is not required, permanently remove/uninstall the Group Replication Plugin from MySQL instances to eliminate the vulnerable component.
- Configuration
Disable or unload the Group Replication Plugin on affected MySQL Server instances until an official fix is available. Use mysqld --disable-plugin or uninstall the plugin via MySQL's plugin management commands (UNINSTALL PLUGIN) as appropriate for your deployment.
MySQL Server (Group Replication Plugin) group_replication (Group Replication Plugin) = disabled/unloaded - Compensating control
Restrict network access to MySQL servers: limit access to trusted IP addresses/subnets, enforce network segmentation, and apply firewall or ACL rules to block untrusted networks and protocols that can reach MySQL until a vendor fix is applied.
- Operational
Monitor MySQL instances for hangs/crashes and ensure automated restart and alerting are in place. Track Oracle/MySQL advisories and apply vendor-supplied patches or updates addressing this vulnerability as soon as they are released.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-34276?
The severity of CVE-2026-34276 is rated as medium with a score of 6.5.
Which MySQL Server versions are affected by CVE-2026-34276?
CVE-2026-34276 affects MySQL Server versions 8.0.0-8.0.45, 8.4.0-8.4.8, and 9.0.0-9.6.0.
How can I mitigate CVE-2026-34276?
To mitigate CVE-2026-34276, it is recommended to upgrade to the latest versions of Oracle MySQL that are not affected.
Who can exploit CVE-2026-34276?
CVE-2026-34276 can be exploited by low privileged attackers who have network access via multiple protocols.
What components of Oracle MySQL are affected by CVE-2026-34276?
The affected component of Oracle MySQL related to CVE-2026-34276 is the Server: Group Replication Plugin.