Denial of Service (DoS) vulnerability in RSSHub

RSSHub is an open source, extensible RSS feed generator. In commits prior to 5c4177441417 passing some special values to the `filter` and `filterout` parameters can cause an abnormally high CPU. This results in an impact on the performance of the servers and RSSHub services which may lead to a denial of service. This issue has been fixed in commit 5c4177441417 and all users are advised to upgrade. There are no known workarounds for this issue.