If the license is GPL, then you can do what you describe, assume you follow the terms of the license. The licensing terms is what matters here, not the fact you're using CPAN as a vehicle to distribute modified software.

In reply to Re: Modifying a CPAN Module and Uploading as a New One? by JavaFan
in thread Modifying a CPAN Module and Uploading as a New One? by Anonymous Monk

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