The bug that never crashed: how I fuzzed an AI's own code sandbox and found it lying to its model

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The bug that never crashed

The scariest bug I caught this month never threw a stack trace. It never paged anyone. It just quietly made an AI agent dumber, on repeat, and handed the blame to the model.

Here is the whole story, because the way I found it turned out to matter more than any single fix.

Where it started

( ( ( (issue)

Each one has its own full write-up with Sentry before/after evidence, if you want the deep dives. This was the story of how they all turned out to be the same bug wearing four different masks.