A breach squad boards an abandoned refueling lattice in a dead system and brings an alien mass back to their damaged frontier carrier.

Once inside, it spreads through suits, bodies, wiring, walls, and command systems until the ship starts behaving like a living enemy.

At first, the failures look like ordinary damage on an old warship: static in cameras, pressure fluctuations, missing drones, silent marines. Then the organism begins turning compartments into tissue, using crew bodies as anchors and learning from every weapon fired against it.

This is "Hostile Takeover" by Sascha Schmidt