Medium (4.3) in rocket.chat rocket.chat. EPSS 0.8% chance of exploitation in the next 30 days.
An improper access control vulnerability exists in Rocket.Chat <v5, <v4.8.2 and <v4.7.5 due to input data in the getUsersOfRoom Meteor server method is not type validated, so that MongoDB query operator objects are accepted by the server, so that instead of a matching rid String a$regex query can be executed, bypassing the room access permission check for every but the first matching room.
Severity
CVSS 3.1
4.3 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
0.8% chance of exploitation in the next 30 days; higher than 56% of CVEs (scores of 2026-10-31)