This affects the package npm-user-validate before 1.0.1. The regex that validates user emails took exponentially longer to process long input strings beginning with @ characters.
{ "github_reviewed_at": "2021-04-20T17:21:44Z", "cwe_ids": [ "CWE-400" ], "github_reviewed": true, "severity": "HIGH", "nvd_published_at": "2020-10-27T15:15:00Z" }