SQLFluff is a modular SQL linter and auto-formatter with support for multiple dialects and templated code. Prior to version 4.1.0, in deployments where untrusted users can provide SQL queries to be linted, an untrusted user can submit a malicious query with deliberate excessive nesting to any application using the parser to trigger a Denial of Service through resource exhaustion. This issue has been patched in version 4.1.0.