as I'm loading a modpack from curseforge, it says that I don't have a high enough version of JEI, despite the fact that I cannot get a higher version, making it completely unplayable.

Same here!

The version required is set by the mod that does the requiring. In this case (or, at least, in the case of the second post, as the original post provides no details) it is JER saying that it requires 9.4.0.

You can find version 9.4.1.110 (the newest as of this writing) at https://www.curseforge.com/minecraft/mc-mods/jei/files/3667756