We have released Spring Security 4.2.13 to address CVE-2019-11272: PlaintextPasswordEncoder authenticates encoded passwords that are null.

Users are encouraged to update immediately.

With Spring Boot, you can override the Spring Security version in Maven like so:

<properties>
    <spring-security.version>4.2.13.RELEASE</spring-security.version>
</properties>

Or in Gradle like so:

ext['spring-security.version'] = '4.2.13.RELEASE'

Note that users of Spring Security 5+ are not affected by this vulnerability.