[This ticket has been merged into MC-262465 and therefore should be marked as a duplicate of it. The original contents are preserved below for clarity's sake.]

The bug

The top texture of the cauldron is a three pixel thick ring. However, the cauldron model only uses the two outermost pixels, leaving the innermost ring completely unused. This is effectively an identical situation to MC-262453. Both the vanilla textures and Programmer Art are affected.

These pixels also first appeared here in release 1.8's development, but, again, never ended up being removed and the Texture Update did not resolve this.

How to fix

An easy fix - just replace the vanilla cauldron top texture file with the one attached, and replace Programmer Art's with the fixed Programmer Art top texture as well.