Researchers discover 'postural manipulation' technique that can reverse LLM decisions without triggering any security filters or leaving detectable traces.

A new attack method uses ordinary language hidden in conversation context to subtly shift how AI models reason about decisions before receiving instructions

Testing across four frontier models showed the same question produced binary decision reversals depending on prior conversation content, with no adversarial signatures

The technique is particularly dangerous in agentic systems where an early 'posture' can survive summarization and appear as independent expert judgment in downstream agents

The vulnerability bypasses all current LLM filters, leaves no payload, injection signature, or log trace, making it undetectable by existing security measures

Coordinated disclosure was made to Anthropic and OpenAI before publication