CVE-2021-37630

Name: CVE-2021-37630
Creator: NVD / NIST
Published: 2021-09-07T20:15:07.847+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.16%

Last modified Jun 17, 2026

CVE-2021-37630 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 1.16% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

1.16%

63.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Circles	< 0.19.5
Nextcloud	Circles	>= 0.20.0, < 0.20.11
Nextcloud	Circles	>= 0.21.0, < 0.21.4

References

https://github.com/nextcloud/circles/pull/768Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-56j9-3rj4-wvgmThird Party Advisory
https://hackerone.com/reports/1257624Permissions Required, Third Party Advisory
https://github.com/nextcloud/circles/pull/768Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-56j9-3rj4-wvgmThird Party Advisory
https://hackerone.com/reports/1257624Permissions Required, Third Party Advisory

Timeline

Published: Sep 7, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-37630?

How severe is CVE-2021-37630?

CVE-2021-37630 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.16% probability of exploitation in the next 30 days.

How do I fix CVE-2021-37630?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-37630?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST