What happened to Venus with a Veil (1531), a possible forgery
It was confirmed to be a forgery.  The most recent news I could find about the story was from 2019, but it indicates that experts had determined that the painting, as well as a number of others sold by Giulano Ruffini, was a modern forgery.

The first painting identified in the case was a Lucas Cranach the Elder Venus, seized by French authorities during a 2016 exhibition of the collection of the Prince of Liechtenstein at the Caumont Centre d’Art in Aix. The prince had purchased the work from Ruffini.
Suspicions quickly arose about other paintings sold by the collector. Sotheby’s tapped scientist and art conservator James Martin of the Massachusetts-based authentication firm Orion Analytical to take a look at a purported Frans Hals work, and a painting attributed to Parmigianino. He found both to be modern fakes, leading Sotheby’s to refund the buyers.

When I first saw an image of the Venus With a Veil, I thought it looked extremely familiar and very much like Cranach.  I thought I had probably seen it before, but I am not actually a particular fan of Cranach, and I just happened to have seen a lot of his works at the Borgese Gallery in Rome, which has an extensive collection.  It would actually be quite unlikely that I had ever seen one of the master's more obscure works.
But no, I had not actually seen it before.  I was instead thinking of this Adam and Eve by Cranach.  Compare the outlines of the womens' ears.  They are actually almost identical, much more similar than you would expect two of Cranach's ears to be.  Their foot positioning are also eerily alike.  Although Cranach evidently liked that pose, his other renderings of it were not so similar.