US cybersecurity officials are contemplating a significant reduction in the time allowed for government agencies to address critical IT vulnerabilities, potentially slashing the response deadline from two weeks to just three days. This decision is driven by the increasing capabilities of AI tools, such as Anthropic's Mythos and OpenAI's GPT-5.4-Cyber, which can rapidly identify and exploit software flaws. As a result, hackers may now act within hours rather than days or weeks. Stephen Boyer, founder of cybersecurity firm Bitsight, emphasized the urgency for civil agencies to adapt quickly to these evolving threats. The discussions are led by Nick Andersen, acting chief of the Cybersecurity and Infrastructure Security Agency (CISA), and Sean Cairncross, the US national cyber director. While the move aims to enhance cybersecurity measures, experts like Nitin Natarajan and Kecia Hoyt caution that the existing strain on CISA's resources could hinder effective implementation. The banking industry and other sectors are also on alert, as they navigate the implications of these advanced AI technologies.