Hi!

I did some tests, and it looks like a change from 1.651.1 to 1.651.2 broke the old stable releases. See below for details:
1.645 ok
1.648 ok
1.650 ok
1.651.1 ok
1.651.2 not ok <--- broken
1.658 ok
2.5 not ok
2.7 not ok

See below what i can see in the jenkins log with 1.651.2 when doing a release build. These messages repeat quite often for a single build (Matrix build 2x3)

{{
Jun 09, 2016 8:45:07 AM WARNUNG hudson.model.ParametersAction filter
Skipped parameter `MY_TEST_VARIABLE_1` as it is undefined on `MY_TEST_BUILD_CONFIG`. Set `-Dhudson.model.ParametersAction.keepUndefinedParameters`=true to allow undefined parameters to be injected as environment variables or `-Dhudson.model.ParametersAction.safeParameters=[comma-separated list]` to whitelist specific parameter names, even though it represents a security breach

Jun 09, 2016 8:45:07 AM WARNUNG hudson.model.ParametersAction filter
Skipped parameter `MY_TEST_VARIABLE_2` as it is undefined on `MY_TEST_BUILD_CONFIG`. Set `-Dhudson.model.ParametersAction.keepUndefinedParameters`=true to allow undefined parameters to be injected as environment variables or `-Dhudson.model.ParametersAction.safeParameters=[comma-separated list]` to whitelist specific parameter names, even though it represents a security breach

Jun 09, 2016 8:45:07 AM WARNUNG hudson.model.ParametersAction filter
Skipped parameter `MY_TEST_VARIABLE_3` as it is undefined on `MY_TEST_BUILD_CONFIG`. Set `-Dhudson.model.ParametersAction.keepUndefinedParameters`=true to allow undefined parameters to be injected as environment variables or `-Dhudson.model.ParametersAction.safeParameters=[comma-separated list]` to whitelist specific parameter names, even though it represents a security breach
}}

I found a workaround that I used to deal with this issue.
My project(s) that use the release plugin did not use any parameters, so I added the same string parameter label as a build parameter. This allowed the release plugin sting parameter to overwrite/update the build parameter and keep my workflow the same.
I hope this helps others with the same issue.

I am using Jenkins 2.8 with Release Plugin 2.5.4

Maybe it's a SECURITY-170 regression.
If yes, it's a duplicate of JENKINS-34996

Another workaround:
start jenkins with the Java option:

-Dhudson.model.ParametersAction.keepUndefinedParameters=true

Up! for this ticket.
We have the same issue with all jobs, that make releases over the Jenkins Release Plugin

We also have this issue. We upgraded today to LTS 2.7.1

https://github.com/jenkinsci/release-plugin/pull/17 is expected to fix it. CC amuniz. Related issue - JENKINS-34996
Issue and workarounds are referenced here: https://wiki.jenkins-ci.org/display/JENKINS/Plugins+affected+by+fix+for+SECURITY-170

Yes, that PR fixes this, it just needs merge and release.

Released it in 2.6