The environment variables still spreads around the jobs. Try the following:

• Configure a maven job
• Use the Inject "Inject environment variables to the build process" checkbox and write something into the "Properties Content" box
• Start the job

You will notice the following (during the run of the maven job)

• Start a free style job that prints all environment variables
• It will print the injected variables from the maven job

• Configure another maven job
• Use the same injection method and the same variable to be injected
• Start the job

If the first job is still running, it will adept the environment from the second maven job!