FlagThis — Daily Cybersecurity Intelligence Briefing

Researchers from Hacktron AI executed a multi-stage breach of OpenAI’s internal infrastructure in under 72 hours by utilizing Anthropic’s Claude Opus 5 to automate vulnerability discovery and exploit development. The attack chain began with the identification of a critical authentication bypass flaw in the Single Sign-On (SSO) implementation of the OpenAI community forum. By leveraging AI-generated payloads to hijack employee accounts, attackers achieved lateral movement from the community-facing asset into OpenAI's internal corporate network, ultimately gaining unauthorized access to internal source code repositories. The breach concluded with a non-malicious pull request to prove the exploit's viability.