Google Site Kit Plugin Ships Hot Fix for Critical Error That Caused Broken Websites

Google published an update to its Site Kit plugin for WordPress this afternoon with a hot fix for a critical issue affecting an unknown number of users. Reports of broken websites were popping up on Twitter and in the plugin’s support forum on WordPress.org. Users affected by the issue reported having a critical error on all sites using Site Kit, which forced deactivation of the plugin in recovery mode. In some cases it prevented them from accessing their dashboards.

“On Wednesday, August 11, we identified a fatal error in the Site Kit plugin that could be triggered by other plugins or themes using an unprefixed version of Composer,” Google Site Kit Support Lead Bethany Chobanian Lang said in a pinned post on the support forum.

Version 1.38.1 contains a hot fix for this issue, since it was critical enough to take down users’ websites. The plugin’s maintainers began investigating the issue less than 24 hours ago but are still not sure which plugins trigger the error due to their usage of Composer.

“The reports do not include which specific plugins or themes were causing this, but the error message clearly highlighted the code in Site Kit that was the problem,” Google Developer Relations Engineer Felix Arntz said. “Technically, that problematic code had been in Site Kit since several versions ago (months back), so maybe another plugin/theme recently got updated with new code that exposed the problem.”

After looking at popular plugins, Arntz said he hasn’t been able to find one so far that would have triggered the problem. Given Site Kit’s broad usage, other affected sites are bound to turn up once users realize there is a problem. Google launched the plugin in 2019 and has since amassed more than a million active installations. The majority of the plugin’s user base is running older versions, which may or may not be affected by the current issue.

WordPress.org shows 35.6% of the plugin’s users are on version 1.38.x. The hot fix is not backported for older releases, but users running Site Kit version 1.38 with background updates enabled should automatically receive the fix.