In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels
event in force.
{ "github_reviewed": true, "nvd_published_at": "2018-06-14T21:29:00Z", "cwe_ids": [], "github_reviewed_at": "2023-07-22T00:05:35Z", "severity": "HIGH" }