Bug 2557856 (CVE-2026-101781)

Summary: CVE-2026-101781 mysql: mysql: Server takeover via Group Replication GCS
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in MySQL's Group Replication Group Communication System (GCS). An unauthenticated attacker located on the same adjacent network segment can exploit this vulnerability without requiring privileges or user interaction. Successful exploitation allows the attacker to take over the MySQL server, leading to unauthorized data disclosure, data modification, and denial of service.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2558766, 2558767    
Bug Blocks:    

Description OSIDB Bzimport 2026-10-21 00:33:26 UTC
Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Server: Group Replication GCS).  Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and  26.7.0-26.7.1. Easily exploitable vulnerability allows unauthenticated attacker with access to the physical communication segment attached to the hardware where the MySQL Server, MySQL Cluster executes to compromise MySQL Server, MySQL Cluster.  Successful attacks of this vulnerability can result in takeover of MySQL Server, MySQL Cluster. CVSS 3.1 Base Score 8.8 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).