Is this tree imploding?
This looks like a slime flux or wetwood disease, it's bacterial and can cause oozing in several different types of trees, but is pretty common in oak. There's not a whole lot you can do. The bacteria that causes it is non-pathogenic for the most part.
Here's more information on it: https://extension.umd.edu/hgic/topics/slime-flux-and-wetwood
Hope this helps.