There have been instances of agents using edge cases like bugs in physics engines, repetitive behavior in games or word repetition in text prediction to cheat their reward function. However, these agents are arguably still contained, as while they explore the extremes of the state space of the simulation they don't expand their action space beyond what is possible in the simulation.
The Pokémon Yellow Total Control Hack shows that in some systems, it is possible to gain full control of a computer by exploiting bugs in the hardware or software (here: memory corruption), enabling the agent to even completely reprogram the system 'from within', just using the normal inputs.
Do you know of similar extreme examples where an AI agent went far beyond what was intended with the simulation environment and expanded its action space?