Apache CXF using eclipse: A required class was missing while executing org.apache.cxf:cxf-codegen-plugin:3.2.:wsdl2java - eclipse

Question

When trying to build our project from within Eclipse I keep getting the following error:
Execution generate-sources of goal
org.apache.cxf:cxf-codegen-plugin:3.2.0:wsdl2java failed: A required
class was missing while executing
org.apache.cxf:cxf-codegen-plugin:3.2.0:wsdl2java:
javax/xml/bind/annotation/adapters/HexBinaryAdapter
The reason for that is that - while we still compile for a Java-8 target environment - the tool chain (i.e. Eclipse, M2E (Eclipe's Maven-plugin), Maven, and CXF) is executed using Java-11.
In Java 9+ javax/xml/bind is not part of the rt.jar anymore, hence the class is missing when the plugin tries to start up. Elsewhere I found that one can enable it by specifying an "--add-modules java.xml.bind" JVM option.
I tried adding that option to the MAVEN_OPTS environment variable but that is apparently ignored when M2E starts up Maven (and with it the CXF plugin) in a separate VM.
Next I tried to specify that option in the plugin's configuration in the pom.xml like so:
<build>
<plugins>
<plugin>
<groupId>org.apache.cxf</groupId>
<artifactId>cxf-codegen-plugin</artifactId>
<version>${cxf.version}</version>
<executions>
<execution>
<id>generate-sources</id>
<phase>generate-sources</phase>
<configuration>
<fork>true</fork>
<additionalJvmArgs>--add-modules java.xml.bind</additionalJvmArgs>
...
</configuration>
<goals>
<goal>wsdl2java</goal>
</goals>
</execution>
</executions>
...
... but that also didn't fly. :-(
Any idea anyone, how and where one can specify that option or how I can make the former standard javax-classes available to a Maven-plugin running under Java 9+ (when executed from Eclipse M2E) ?
Just in case: this is NOT an Eclipse or M2E issues! Even when I start Maven on the command line using Java 9+ I get:
...
[ERROR] Failed to execute goal org.apache.cxf:cxf-codegen-plugin:3.2.0:wsdl2java (generate-sources) on project my_project: Execution generate-sources of goal org.apache.cxf:cxf-codegen-plugin:3.2.0:wsdl2java failed: A required class was missing while executing org.apache.cxf:cxf-codegen-plugin:3.2.0:wsdl2java: javax/xml/bind/annotation/adapters/HexBinaryAdapter