CVE-2021-37630 json
Secret Circle can be joined without approval in Nextcloud Circles
published 5y ago modified 4mo ago also EUVD-2021-24186
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known
Summary
Nextcloud Circles is an open source social network built for the nextcloud ecosystem. In affected versions the Nextcloud Circles application allowed any user to join any "Secret Circle" without approval by the Circle owner leaking private information. It is recommended that Nextcloud Circles is upgraded to 0.19.15, 0.20.11 or 0.21.4. There are no workarounds for this issue.
Patch / fix
Is CVE-2021-37630 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:P/I:N/A:N |
Affected products
- nextcloud security-advisories
Classification
- Weakness
-
- CWE-639 Authorization Bypass Through User-Controlled Key
References
-
github.com
/nextcloud/circles/pull/768
patch, third-party-advisory
-
github.com
/nextcloud/security-advisories/security/advisories/GHSA-56j9-3rj4-wvgm
third-party-advisory
-
hackerone.com
/reports/1257624
permissions-required, third-party-advisory
Sources
- CVE List CVE-2021-37630
- NVD CVE-2021-37630
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.