Item invalid life stat - Hypnotic Veil Rusted Cuirass

Expected result: HP increases by the amount that the description says

Actual result: HP increases by more than the description says

Steps to reproduce:
1. Find item from Rust King
2. Equip item

Item: Hypnotic Veil Rusted Cuirass

I've received a rare item which says +16 maximum hp, but when I equip it, I gain +26 maximum hp. I have no passives that increase max hp.

I've tested equipping another chest item with +10 maximum hp, and that correctly increases my max hp by 10, so I believe this item is the one that's bugged.

See images in the link.

https://imgur.com/a/y8DwL9u