MC version: 1.12.2
Mod: 7.0.1
Forge: 14.23.3.2695

Settings: mobGriefing = false - mobGriefing villager = true - mobGriefing sheep = true

Endermen don't pick up items, but they seem to be able to destroy their surroundings when attacking me. Say, if I'm holed up in a small place, they try to destroy things to get to me.

For reference, Creepers exploding behave as expected. Their explosions don't damage their surroundings.

Edit: Just saw it happen a lot more clearly now. The Endermen are able to hit things with their arms. This knocks blocks off, or breaks them completely (glass).

I'm not able to reproduce this either with or without my mod installed, also looking at the code I can't see anything to suggest that this behaviour is possible.

Are you using any other mods which could be changing the Enderman behaviour?

Yep. I feel silly now. I did the typical disabling of other mods one by one, and found out there's a feature in Quark that's called "Enderman Anti-Cheese" which specifically has Endermen doing this.

Disabling the feature has everything working as expected. I apologize for any wasted time.

No need to apologise, I'm just happy it's resolved.
Thanks for taking the time to verify.