{"id":"CVE-2021-1771","aliases":["EUVD-2021-7235","GHSA-cv82-wvv8-3jrx"],"status":"published","title":"This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2,...","description":"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.","severity":{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","level":"low","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.00565,"percentile":0.47215,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2021-04-02T17:56:23Z","modified":"2026-06-17T03:32:31Z","products":[{"vendor":"apple","product":"mac_os_x"},{"vendor":"apple","product":"macos"}],"references":[{"url":"https://support.apple.com/en-us/HT212147","tags":["x_refsource_MISC","x_transferred","Release Notes","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-1771"},{"url":"https://github.com/advisories/GHSA-cv82-wvv8-3jrx"}],"sources":{"cve":[{"id":"CVE-2021-1771","description":"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.","status":"published","published":"2021-04-02T17:56:23Z","modified":"2024-08-03T16:25:04.595Z","updated_at":"2026-11-02T14:33:08.045407Z"}],"euvd":[{"id":"EUVD-2021-7235","description":"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.","status":"published","published":"2021-04-02T17:56:23Z","modified":"2024-08-03T16:25:04Z","updated_at":"2026-11-03T03:25:15.150715Z"}],"ghsa":[{"id":"GHSA-cv82-wvv8-3jrx","title":"This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2,...","description":"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.","status":"published","published":"2022-05-24T17:46:19Z","modified":"2023-01-29T05:07:05Z","updated_at":"2026-11-02T14:46:08.723565Z"}],"nvd":[{"id":"CVE-2021-1771","description":"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.","status":"published","published":"2021-04-02T18:15:20.7Z","modified":"2026-06-17T03:32:31.717Z","cvss":[{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","level":"low","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:06:51.197859Z"}]}}