Random "lost connection" error not associated with a player: java.lang.IndexOutOfBoundsException: readerIndex + length exceeds writerIndex: PooledUnsafeDirectByteBuf

My server was left on and a random IP from France caused an error. The IP wasn't associated with a player name, and none of the guys that go on my server live anywhere near France... so I figured it might be some kind of exploit attempt or port scanning bot.

The attached log contains the error as well, but here it is for easy viewing:

[10:11:07] [Server thread/INFO]: /163.172.139.143:56026 lost connection: Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(18) + length(1) exceeds writerIndex(18): PooledUnsafeDirectByteBuf(ridx: 18, widx: 18, cap: 18)

I tried googling for similar 'lost connection' errors, but I kept seeing unrelated stuff instead... so I decided I'd write my own bug report.

If this is not a vulnerable security risk, feel free to un-private this report so that the error can be searched by other users. It's not my IP nor the IP of anyone I know, so I don't care if it's censored or not.