I wanted to bring this to your attention. I am currently using v9.6.10.
Your error comes from WP Cerber’s Bug Hunter module.
This internal system has three purposes:
- collecting error information generated by WP Cerber,
- anonymizing sensitive data,
- sending the report to https://downloads.wpcerber.com/bughunter/
where the developers can analyze it and improve the software.
This error is not critical, but depending on the size of your website it may generate a lot of unnecessary noise in your logs.
Bug Hunter is not a security feature and is generally not useful for normal users mainly for developers.
While waiting for a plugin update, you can simply disable this option, especially if you’re not a developer.
You can find it here:
WP Cerber Dashboard / General Settings / Collect WP Cerber software errors
(this option is located right after the plugin update settings).
About the technical cause:
This is a real bug in the code, what developers call a rare edge case It only happens when a specific line in the error log contains unexpected data.
The function crb_strip_query_params() requires a string (standard behaviour in PHP 8).
But sometimes $error[7] the request URL is missing or null, which triggers a TypeError before the function can run.
A small safeguard in the code would fix the issue.