As per the MediaWiki version lifecycle[1], I would like to announce the
formal end of life (EOL) of MediaWiki 1.31 as of tomorrow, Thursday
September 30, 2021, coinciding with the final security and maintenance
release for the branch, 1.31.16.
This means that MediaWiki 1.31 will no longer receive maintenance or
security backports. It is therefore strongly discouraged that you continue
to use it.
It is recommended to upgrade to MediaWiki 1.35, the current Long Term
Support (LTS) version which is not due to become EOL until September 2023.
MediaWiki 1.35 bumps the required PHP version from 7.0 in 1.31 (which is
unsupported upstream), to PHP 7.3.19 or later.
Thanks!
Sam Reed
[1]
https://www.mediawiki.org/wiki/Version_lifecycle