Discourse is a platform for community discussion. The message serializer uses the full list of expanded chat mentions (@all and @here) which can lead to a very long array of users. This issue was patched in versions 3.1.4 and beta 3.2.0.beta5. Referenceshttps://github.com/discourse/discourse/security/advisories/GHSA-hf2v-r5xm-8p37
