So I was careless and after playing left my clarinet assembled on a stand for about 2 weeks while I went on vacation. When I took it apart I noticed the joints were loose. Any way I can fix this or will I have to get them all replaced? Thanks.
If by "loose" you mean the corks are overcompressed so the body parts wobble, then the corks may recover after you leave the clarinet disassembled for a couple days (and maybe gently hydrate the corks).
If you mean the corks themselves came loose, then they need to be replaced.
That said, I find it rather unusual that the joints' fit would go bad whether or not the clarinet was left assembled. Was this during winter months (very low humidity)?