Noun
oversharer (plural oversharers)
One who overshares.
It's interesting to see how other people react to an oversharer. Lena Dunham
Anderson has no filter and is a self-confessed “oversharer” while Bartholemew said she is a little more reticent. Source: Internet
I think he thought I was fun, if not a bit blunt and a bit of an oversharer. Source: Internet