Please make sure you are running the most recent release. Only the latest stable version of Vieb receives security updates. There is no official backporting for patches of any kind at this moment.
Please consider the impact of using Github's public issues for security problems. In general: use Github's "Report a vulnerability" feature in the "Security" tab. This ensures that only core developers of Vieb will have access until it is fixed.
If you have any questions on this or anything else you can ask them via Matrix or Telegram.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License in ./LICENSE
for more details.