CVE-2021-35642: 
MySQL vulnerability analysis and mitigation

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.26 and prior. This easily exploitable vulnerability allows high 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 (Oracle CPUOct2021, NetApp Advisory).

The vulnerability has been assigned a CVSS v3.1 Base Score of 4.9 (Medium severity). The attack vector is Network based with Low attack complexity. It requires High privileges and No user interaction. The scope is Unchanged with No impact on Confidentiality and Integrity but High impact on Availability (NetApp Advisory).

Successful exploitation of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete Denial of Service) of MySQL Server. The vulnerability specifically affects the Server Optimizer component (Oracle CPUOct2021).

Oracle has released patches to address this vulnerability in MySQL version 8.0.27. Users are strongly recommended to update to this version or later. Ubuntu users can update their systems through standard system updates to mysql-server-8.0 version 8.0.27 for Ubuntu 20.04, 21.04, and 21.10 (Ubuntu Notice).