Flaw Lets Researchers Decode Hidden Reasoning From OpenAI, Anthropic, Google APIs

Researchers decoded 315,320 hidden thinking blocks across 6,708 public agent traces from OpenAI, Anthropic, and Google APIs, recovering 62 API keys, 33 passwords, 24 access tokens, and 7 private keys. The paper "Stealing Reasoning Traces from Proprietary LLM APIs" also found evidence some Chinese AI may be trained on leading US models. Providers mitigated the attacks as of August 2026.