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CVE-2021-1771
This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security…
Low3.3EPSS 0.56%
- Published
- Updated
- Reserved
- Assigned by
- apple
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.
Timeline
ID reserved
By apple
- 4 months later
· 4 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Low3.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.56% · top 53% of all CVEs (7 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.3.
Weakness
- A user that is removed from an iMessage group could rejoin the group
Affected products
References (1)
- https://support.apple.com/en-us/HT212147 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-1771)Record last updated .