The agent said it fixed the bug. The original PoC still fired.

Reddit r/AI_Agents News

Summary

A post argues that coding agents often claim to fix security bugs while leaving the original PoC still exploitable, and proposes freezing the PoC, evidence, and missed check as fixtures for every rejected action so patches are verified against the trigger, not just the diff.

A coding agent closes a security ticket. The patch is clean. Tests pass. The diff matches the advisory. Then someone runs the original PoC against the patched build. It still fires. The agent fixed a different path. The failure isn't the model's reasoning. It's the check: we verified the diff, not the trigger. The check that would have caught it is simple: freeze the PoC, apply the patch, run the PoC. If the trigger has to change to reproduce, it's a different bug. Now every rejected action leaves a fixture: the exact trigger, the evidence the agent cited, and the check that would have caught it. The queue clears; the fixture stays. What do you freeze first when an agent says "fixed"?
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