The PHP project has announced a security release that fixes two critical security vulnerabilities discovered in PHP.

Due to the critical severity of the issues, site owners are encouraged to immediately update their installations of PHP. Your web host may already be working to update PHP and put web application firewall (WAF) rules in place to mitigate the vulnerabilities, but you should still check for updates from your web host and, if necessary, update PHP as soon as possible.

Within WordPress, you can see which version of PHP your site runs under Tools > Site Health > Info > Server. Many web hosts provide this information in your web hosting administration panel too.

These vulnerabilities are not specific to WordPress and affect any server that hosts a PHP application. No WordPress update is required or planned for these issues.

Versions of PHP prior to 8.2 no longer receive security updates from the PHP project.

If your site runs a version prior to this and you manage your own web hosting, you should consider taking your server offline while you prepare to update to a newer version of PHP. This advice is being published by several national cyber security agencies. To quote the UK National Cyber Security Centre:

Where immediate remediation is not feasible, organisations should consider taking the system offline until it can be fully mitigated.

Further information on wordpress.org:

• Get a faster, more secure website: update PHP today
• PHP Compatibility and WordPress Versions
• FAQ My site was hacked