From yesterday's PO! thread [1] [2]:

- https://phrack.org/

- https://tmpout.sh/

- https://www.hugi.scene.org/

- https://lainzine.org/archive

- https://inteltechniques.com/magazine.html

- https://n-o-d-e.net/zine/

- https://increment.com/issues/

- https://pocorgtfo.hacke.rs/

Not all of them are active though.

[1] https://news.ycombinator.com/item?id=46134188

[2] https://news.ycombinator.com/item?id=46130469