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Removing emails from circles does not revoke access to shared items (NC-SA-2019-013)

6th October 2019

Risk level: Low

CVSS v3 Base Score: 2 (AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N)

CWE: Improper Authorization (CWE-285)

HackerOne report: 673724


Improper authorization in the Circles app 0.17.7 causes retaining access when an email address was removed from a circle.

Affected Software

  • Nextcloud Circles < 0.17.8 (CVE-2019-15610)
  • Nextcloud Circles < 0.16.11 (CVE-2019-15610)

Action Taken

The error has been fixed.


It is recommended that the Circles app is upgraded to 0.17.8.


The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:

  • michag86 - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.

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