There's a phrase expressing this that I heard a few years ago that I found completely charming:
- The scuttlebutt has it...
Example:
The scuttlebutt has it that Alice and Bob have been exchanging more than just encrypted messages, if you know what I mean.
"Scuttlebutt" is apparently the 19th Century sailors' equivalent of "water cooler", According to WikiPedia, and others.
Basically:
Water for immediate consumption on a sailing ship was conventionally stored in a scuttled butt: a butt (cask) which had been scuttled by making a hole in it so the water could be withdrawn. Since sailors exchanged gossip when they gathered at the scuttlebutt for a drink of water, scuttlebutt became Navy slang for gossip or rumours