A new update for GTA Online, version 1.09, has eradicated a number of cash and player progression glitches, on top of strengthening overall anti-cheat measures in the online multiplayer side of GTA 5.
Rockstar hasn't said which exact exploits have been taken care of in the patch notes, nor has the studio offered any context. We've followed up with Rockstar for more information and will update this post accordingly.