PingCAP TiDB v8.1.0 was discovered to contain a buffer overflow via the component (*Column).GetDecimal. This allows attackers to cause a Denial of Service (DoS) via a crafted input to the 'RemoveUnnecessaryFirstRow', it will check the expression between 'Agg' and 'GroupBy', but does not check the return type. NOTE: PingCAP disputes this, arguing that reproduction did not cause the security impact of service interruption to other users. They maintain it is a complex query bug in the product but not a DoS.