As of Season 9, Walden and Judith are good friends.
In "Nice to Meet You, Walden Schmidt", when Judith brings Jake over to the beach house for his weekend stay, they are both stunned to find Alan being hugged by a naked Walden. After this, Alan tells them that Walden is going to by the beach house. After the introduction as Judith watches Walden walk back to his room still in the nude, she approves.
In "Big Girls Don't Throw Food", After hearing about Jake being approved for his decision to drop out of school, Judith is angry by this news and comes over to the beach pad to talk to Walden about what he said to Jake. As Walden sits on the couch reeling from his dinner with Bridget not going so well, Judith still remains angry toward him after learning he was the one that told Jake about dropping out of school to make millions but when Walden starts telling Judith about how he and Bridget met and how they were high school sweethearts, Judith loses her tone and starts to warm up to him, eventually bad about his sadness over losing Bridget. As Walden says that he doesn't know what he is going to do after losing Bridget, Judith comforts him with a hug telling him everything's going to be okay and asks him if there was anything that she could do to cheer him up. Walden asks her what could she do to cheer him up and she kisses him and the pair end up making out on the couch while, unbeknownst to them, Jake gets the whole scene on video on his phone so he could use it to blackmail Judith into letting him drop out of high school.