Though there's no official word on a patch, VG247 reports that a new version of Grand Theft Auto V is now available. The good news is that this apparently addresses framerate issues that followed the last patch, but the bad news is this may break support for some modifications. They offer this quote on the topic from Rockstar:

“We also received some reports linking decreased performance when using Story Mode mods to TU 1.28. As mentioned previously, we are not actively targeting players using mods in Story Mode, nor are we explicitly implementing protections against them in-game,” said the developer.

“Our primary focus is on protecting GTA Online against modifications that could give players an unfair advantage, disrupt gameplay, or cause griefing. However, as a reminder, mods are still unauthorized and as such, Title Updates may cause Story Mode mods to behave in unexpected ways because they are not supported or tested, and players run them at their own risk.”