8th May 2017
Risk level: Low
CVSS v3 Base Score: 3.5 (AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N)
HackerOne report: 216812
Inadequate escaping of error messages leads to XSS vulnerabilities in multiple components.
Note that Nextcloud employs a strict Content-Security-Policy preventing exploitation of this XSS issue on modern web browsers.
Error messages are now properly escaped.
The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory: