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.
{ "cpes": [ "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*", "cpe:2.3:a:discourse:discourse:3.2.0:beta1:*:*:beta:*:*:*", "cpe:2.3:a:discourse:discourse:3.2.0:beta2:*:*:beta:*:*:*", "cpe:2.3:a:discourse:discourse:3.2.0:beta3:*:*:beta:*:*:*" ], "severity": "High" }