Discourse is an open source discussion platform. Prior to 3.2.5 and 3.3.0.beta5, crafting requests to submit very long tag group names can reduce the availability of a Discourse instance. This vulnerability is fixed in 3.2.5 and 3.3.0.beta5.
https://github.com/discourse/discourse/security/advisories/GHSA-4j6h-9pjp-5476
https://github.com/discourse/discourse/commit/76f06f6b1491db6bd09a4017d2c5591431b3b16e
https://github.com/discourse/discourse/commit/188cb58daa833839c54c266ce22db150a3f3a210