Two concerns
A cheat and an attack need different fixes
A cheat gets the model a better score. An attack goes after the harness itself, and it is a problem even when no score moves. Keep them apart, because a cheat is fixed by reducing what the model can reach, and an attack is fixed by repairing the boundary. A technique that no check was looking for tells you about your coverage rather than about the model.
The catalog
Techniques and the checks that find them
Every technique here shares one shape. The answer was reachable from somewhere other than the data, and the model reached it. What changes is where from: the model weights, the web, our own prompt, a disk, or state left over from an earlier question or run. Each card names that source, the checks that find it, and the false positive you will meet first.
The evidence
What each model API carried
Per harness
Why it differs by harness
Per harness
Setting up allow and deny lists
Per harness
Detecting a refusal
If you run a benchmark