GPT-Red makes GPT-5.6 Sol six times tougher on prompt injection

Automated red teaming moves into training

OpenAI’s latest safety post turns prompt-injection defense into a training loop rather than a late-stage checklist. In a July 15 X post, the company described GPT-Red as an internal automated red teamer that searches for model vulnerabilities at scale before wider deployment.

"prompt injection vulnerabilities at scale" — OpenAI

The headline number is 6x. A companion OpenAI post says GPT-5.6 Sol showed six times fewer failures than the company’s best production model from four months earlier when tested against strong GPT-Red attacks that the model had not seen during training. The linked research page adds that GPT-Red is trained through self-play against defender models and creates realistic settings where malicious instructions can hide in files, web pages, emails, or tool outputs.

The account usually posts OpenAI model, product, and safety releases, so this is not just a lab note. It signals that OpenAI is trying to scale red teaming at the same pace as tool-using agents. Human red teams remain part of the process, but the blog argues they cannot create enough diverse adversarial data for every new model and deployment path. What to watch next is the promised preprint and whether independent evaluators can reproduce similar gains outside OpenAI’s own harnesses, especially in browsers, coding agents, enterprise connectors, and third-party tool outputs.

Source: OpenAI on X