The Division's first Incursion (opens in new tab), Falcon Lost, has been patched to make it ever so slightly harder to exploit (opens in new tab). It won't be impossible, of course—particularly if network expert Glenn Fiedler's damning assessment (opens in new tab) of The Division's network model is correct—but any improvement is welcome.
Most importantly, players are no longer able to shoot into the Incursion from outside it. Cheaters had previously found their way into untextured scenery behind the boss room that allowed bullets in but nothing out. A second bug that allowed players to climb through the ceiling by using a ladder while playing the jumping jack emote has also been exterminated.
The most widespread issue remains, however. It still appears to be possible to use your portable shield to vault through solid walls, making Falcon Lost easy farming for the unscrupulous.