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Agents2026-06-27 · source-backed

"Instruction Bleed" names a structural vulnerability in prompt-composed agents.

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A June 26 paper (arXiv:2606.26356) analyzes how instructions from one module of a prompt-composed agent leak into and corrupt another module's behavior. (arXiv) This is the failure mode lurking under the "stitch agents from composable skills" pattern everyone's adopting, including me. Module boundaries you treat as organizational convenience are actually a security and correctness problem. If skill A's instructions bleed into skill B, you get behavior neither skill author intended. Treat boundaries as real isolation, not folder structure.

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2026-06-27-instruction-bleed-names-a-structural-vulnerability-in-prompt-composed-agents
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source-backed, canonical briefing excerpt