NamelessMC is a free, easy to use & powerful website software for Minecraft servers. In version 2.1.4 and prior, the s parameter in GET requests for forum search functionality lacks length validation, allowing attackers to submit excessively long search queries. This oversight can lead to performance degradation and potential denial-of-service (DoS) attacks. This issue has been patched in version 2.2.0.
https://github.com/NamelessMC/Nameless/security/advisories/GHSA-4hrq-rf96-c2jm
https://github.com/NamelessMC/Nameless/releases/tag/v2.2.0
https://github.com/NamelessMC/Nameless/commit/f5341e56930a98978171e0a871d60f19ab30ebdd