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OpenAI Help: Lockdown Mode

infonewsLLM-Specific

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Source: Simon Willison's WeblogJune 5, 2026

Summary

OpenAI has released Lockdown Mode, a security feature that prevents the final stage of data exfiltration (stealing and sending sensitive information) from prompt injection attacks (tricking an AI by hiding malicious instructions in its input) by blocking outbound network requests. However, Lockdown Mode does not stop prompt injections from appearing in the content ChatGPT processes, meaning attackers can still manipulate the AI's responses through cached web content or uploaded files.

Solution / Mitigation

Enable Lockdown Mode, which is rolling out to eligible personal accounts (Free, Go, Plus, and Pro tiers) and self-serve ChatGPT Business accounts. According to the source, Lockdown Mode uses deterministic mechanisms (fixed, rule-based processes) to restrict exfiltration vectors, rather than relying on AI systems to detect attacks.