Events Manager 5.12 fixed a reported XSS vulnerability. Whilst the update mitigates the known vulnerability, and we aren’t aware (or do we think there is) of a way to further exploit this, we updated a few template files with some extra security precautions. This is an overabundant precautionary measure, meaning

We’ve released two maintenance updates, including a security fix for a vulnerability found in Events Manager 5.12. We advise that you upgrade as soon as possible to mitigate an XSS vulnerability. We’d like to thank the WordPress Plugin team for doing a fabulous job with keeping the plugin repository safe