This vulnerability in Apache Superset versions prior to 6.0.0 involves a Regular Expression Denial of Service (ReDoS) caused by inefficient regular expression complexity in the sql_parse.py component's SQL_REGEX. The affected regex contains overlapping disjunctions with a common outer quantifier, which can be exploited by an authenticated attacker sending maliciously crafted input strings (notably long sequences of backslashes) to SQL query processing endpoints. This can cause excessive CPU consumption leading to denial of service. The issue is fixed in version 6.0.0. Mitigations include WAF rules targeting suspicious query patterns and rate limiting the /api/v1/chart/data endpoint.

An authenticated attacker can cause a denial of service condition by triggering excessive CPU usage through crafted input strings exploiting the inefficient regular expression in SQL parsing. This impacts availability by potentially making the service unresponsive or slow. There is no indication of privilege escalation, data confidentiality, or integrity impact.

A fix is available in Apache Superset version 6.0.0; users should upgrade to this version to remediate the vulnerability. Until upgrading, implement Web Application Firewall (WAF) rules to detect and block requests with excessively long sequences of backslashes or suspicious repeated patterns in the queries.extras.where parameter. Additionally, apply strict rate limiting on the /api/v1/chart/data endpoint to reduce the impact of potential attacks.