If a request fails the allowedRequestAttributesPattern check a 403 is returned for the request but nothing is visible in the default logging. This check should only fail as a result of server mis-configuration or malicious action. Both cases would benefit from something in the server logs even if only to help people find the right part of the documentation to look at.
Fair point. I'll take a look.
Fixed in: - master for 10.0.0-M6 onwards - 9.0.x for 9.0.36 onwards - 8.5.x for 8.5.56 onwards - 7.0.x for 7.0.105 onwards