CVE-2012-6707

WordPress through 4.8.2 uses a weak MD5-based password hashing algorithm, which makes it easier for attackers to determine cleartext values by leveraging access to the hash values. NOTE: the approach to changing this may not be fully compatible with certain use cases, such as migration of a WordPress site from a web host that uses a recent PHP version to a different web host that uses PHP 5.2. These use cases are plausible (but very unlikely) based on statistics showing widespread deployment of WordPress with obsolete PHP versions.

Source: CVE-2012-6707