sqlparse is a non-validating SQL parser module for Python. In affected versions the SQL parser contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service). This issue was introduced by commit `e75e358`. The vulnerability may lead to Denial of Service (DoS). This issues has been fixed in sqlparse 0.4.4 by commit `c457abd5f`. Users are advised to upgrade. There are no known workarounds for this issue.