Managed hosting is a hosting arrangement in which the provider takes responsibility for operating the server and keeping its software up to date. That typically includes the operating system, the web server and the PHP runtime, along with routine tasks such as monitoring and backups. The customer manages the website itself: its content, code, themes, plugins and user accounts.
The exact scope of "managed" varies between providers and plans. Some handle only the underlying platform, while others also offer application-level services such as CMS updates or malware scanning. The terms of service or plan documentation, not the label alone, show which tasks the provider actually performs.
Managed hosting does not by itself prove that a particular server is patched against a given vulnerability. Providers decide when and how they roll out updates, and they may use vendor backports, staged deployments or maintenance windows, so the timing differs. A provider announcing that a fix is rolling out is also not the same as confirming it has reached your account.
To check your own situation, look for a security notice or status page from the provider, ask support which PHP version and build your site runs on and whether the relevant fix is applied, and confirm any change through the control panel or a test of your own. Whatever the host does, keep your own application code, plugins and credentials up to date, because the provider does not necessarily patch those, and review your site for unexpected files or activity if you suspect a problem.