OpenAI's New Daybreak Platform Uses GPT-5.5 to Find Software Vulnerabilities

OpenAI today launched Daybreak, an answer to Anthropic's Project Glasswing initiative and Mythos AI model. Like Glasswing, Daybreak is a cyber defense effort that will help tech companies find security vulnerabilities in their platforms.

OpenAI says Daybreak is aimed at building cyber defense into software from the start. It builds on OpenAI's April launch of GPT-5.4-Cyber, which the company says has contributed to fixing more than 3,000 vulnerabilities.

Daybreak combines the intelligence of OpenAI models, the extensibility of Codex as an agentic harness, and our partners across the security flywheel to help make the world safer for everyone. Defenders can bring secure code review, threat modeling, patch validation, dependency risk analysis, detection, and remediation guidance into the everyday development loop so software becomes more resilient from the start.

OpenAI CEO Sam Altman said OpenAI would like to work with "as many companies as possible" to help them continuously secure their software against cyber threats. Several companies have already adopted Anthropic's competing Glasswing program, including Apple, Microsoft, Google, and Amazon.

Daybreak uses Codex Security to build an editable threat model from a company's software repository, then it automates monitoring for higher-risk vulnerabilities. Issues that are found can be investigated in an isolated environment.

Companies can request a Daybreak assessment from OpenAI, which includes a vulnerability scan. Pricing is not listed.

There are three models available. GPT-5.5 has standard safeguards for general purpose use, while GPT-5.5 with Trusted Access for Cyber is meant for verified defensive work in authorized environments. GPT-5.5-Cyber is for specialized authorized workflows, and it features stronger verification and account-level controls.

OpenAI is working with industry and government partners ahead of deploying more cyber-capable models in the future.