Sporadically taking damage when I fire my weapons
As of Patch 1.55, this bug has been resolved.
Fixed an issue where player ships could shoot themselves in multiplayer
According to an article on kotaku, this has been confirmed by Sean Murray that it is indeed a bug due to network lag while in multiple player sessions.
Our ships are procedurally generated, as are our weapon stats. The issue you mention affects a subset of ships that players can buy in-game, with certain weapons,” Sean Murray, founder of Hello Games, said over email when Kotaku asked about the bug. “It is generally only seen when multiplayer is active, and is related to network lag in these cases. The issue has been fixed by the team, is in testing, and will be released in a hotfix soon
(emphasis my own)
The community over on reddit are experiencing the same issue. As one user breaks it down, you are essentially shooting your own hit box.
Some players on the steam community state they do not experience this issue when playing solo. They indicate it is likely due to network latency when playing with other players and your ship flys faster than your weapon shoot. I personally have yet to experience this while playing solo, so this is plausible explanation.
A temporary solution, provided by the users on reddit, is to either remain still or fly backwards when shooting your weapons. This in not a too terrible of a solution when destroying asteroids or a small band of pirates, but this makes a swarm of pirates much more difficult.