Golden Creeping Jenny, Gold Moneywort 'Aurea' (Lysimachia nummularia)
Before it was prohibited here (Massachusetts), I bought two plants for use in containers. The client planted them in the beds without telling me, and it took only a few months to become an ineradicable weed, both in the borders and also in the lawn. (This is a no-herbicide garden.)
This plant creeps quickly along the ground and roots at every node. In our heavy soil, the roots are stronger than the stems, and if I pull, the stem snaps above the nearest rooted node. That makes it as hard to remove from the lawn as ground ivy (Glechoma hederacea), which has a similar habit and is also a problem in this garden.
I find that plantings of gold-leafed cultivars need to be monitored for green reversions/seedlings.
This species is native to Europe and widely naturalized throughout the US. There is widespread concern about its invasion of natural habitat, especially in sensitive wetlands.
It can be controlled with 2% glyphosate herbicide.