OpenAI is rolling out a more permissible version of GPT-5.5 — aka "Spud" — to vetted cyber defenders, the company said Thursday. Why it matters : Recent security testing suggests that GPT-5.5 model is nearly as good at finding and exploiting software bugs as Anthropic's Mythos Preview . The capabilities of the new models have sparked an urgent debate in Silicon Valley and the White House about how to keep them out of the hands of bad actors. Driving the news: OpenAI is opening a limited preview of GPT-5.5-Cyber to vetted cyber defenders who are "responsible for securing critical infrastructure," per a press release. A source familiar with GPT-5.5-Cyber's abilities told Axios that they were roughly on par with Mythos. One major recent test put Mythos narrowly ahead. Cyber defenders who are vetted and approved for the highest tier of OpenAI's Trusted Access for Cyber program will receive a version of GPT-5.5 that has fewer guardrails than the publicly available model.…