Check our website's download page to see which versions are still supported and will receive security updates.
If you found a security issue or vulnerability of the software, please report it to Nextcloud's HackerOne.
Your report should include clear steps for reproduction and a classification of the found vulnerability.
If you prefer, you can also send an encrypted email message to security [at] roundcube.net. The PGP key's fingerprint is ACFCF63232B79518E632EC4B0127B799F939816F.
We're dedicated to analyze and fix the reported issues as fast a possible. Usually within days we'll have an update ready. Together with the reporter we plan the releasing and the disclosure of the found and fixed vulnerability. Credits to the reporter are granted and can be included in all public communication if desired.