This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. A user that is removed from an iMessage group could rejoin the group.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mac_os_x | Apple | 10.14 (including) | 10.14.6 (excluding) |
| Mac_os_x | Apple | 10.15 (including) | 10.15.7 (excluding) |
| Mac_os_x | Apple | 10.14.6 (including) | 10.14.6 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2019-001 (including) | 10.14.6-security_update_2019-001 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2019-002 (including) | 10.14.6-security_update_2019-002 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-001 (including) | 10.14.6-security_update_2020-001 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-002 (including) | 10.14.6-security_update_2020-002 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-003 (including) | 10.14.6-security_update_2020-003 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-004 (including) | 10.14.6-security_update_2020-004 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-005 (including) | 10.14.6-security_update_2020-005 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-006 (including) | 10.14.6-security_update_2020-006 (including) |
| Mac_os_x | Apple | 10.14.6-security_update_2020-007 (including) | 10.14.6-security_update_2020-007 (including) |
| Mac_os_x | Apple | 10.14.6-supplemental_update (including) | 10.14.6-supplemental_update (including) |
| Mac_os_x | Apple | 10.14.6-supplemental_update_2 (including) | 10.14.6-supplemental_update_2 (including) |
| Mac_os_x | Apple | 10.15.7 (including) | 10.15.7 (including) |
| Mac_os_x | Apple | 10.15.7-supplemental_update (including) | 10.15.7-supplemental_update (including) |
| Macos | Apple | 11.0 (including) | 11.2 (excluding) |