Maintainers for mutter are Debian GNOME Maintainers <pkg-gnome-maintainers@lists.alioth.debian.org>.
You may want to refer to the following individual bug pages: gir1.2-mutter-11, gir1.2-mutter-12, gir1.2-mutter-14, gir1.2-mutter-3, gir1.2-mutter-7, libmutter-11-0, libmutter-11-dev, libmutter-12-0t64, libmutter-12-dev, libmutter-14-0, libmutter-14-dev, libmutter-3-0, libmutter-3-dev, libmutter-7-0, libmutter-7-dev, libmutter-test-11, libmutter-test-12t64, libmutter-test-14, mutter-11-tests, mutter-12-tests, mutter-14-tests, mutter-common, mutter-common-bin.
You might like to refer to the mutter package page, or to the Package Tracking System.
If you find a bug not listed here, please report it.