Japan's Finance Minister Satsuki Katayama convened an emergency meeting on Friday that included the Financial Services Agency, the Bank of Japan, the National Cybersecurity Office, the country's three largest banks, and Japan Exchange Group. The agenda: what to do about Anthropic's Mythos.

"I told the meeting that this is a crisis that is already at hand, and similar concerns were also voiced by the financial industry," Katayama told reporters.

The decision to create a formal task force makes Japan the first country to stand up a dedicated national response to the cybersecurity implications of a single AI model.

Thousands of Vulnerabilities, Zero Breaches

The trigger is straightforward. Anthropic disclosed that a preview of Mythos uncovered "thousands" of major vulnerabilities across every major operating system and web browser. Experts warn that the model can identify and exploit previously unknown vulnerabilities faster than companies can repair them. For banking, which runs on complex, interconnected, and often decades-old technology stacks, this creates a systemic risk that traditional patching cycles cannot address.

To date, there have been no reported breaches related to Mythos. But Katayama emphasized that the financial system's high level of interconnectedness and real-time operations mean that problems can spread more rapidly than in other sectors.

"Because of this, a cyberattack can immediately spill over into market disruptions and undermine confidence," she said.

A Global Pattern Forming

Japan is not acting in isolation. Regulators across Asia, Europe, and the United States have warned banks to review their defenses and preparedness. Singapore's Monetary Authority has been coordinating with the Cyber Security Agency. South Korea has convened its own meetings. But Japan is the first to formalize the response into a standing task force with representation from the central bank, financial regulators, the cybersecurity apparatus, and private sector institutions.

The AI Post has tracked the Mythos security story across multiple cycles. In April, we reported on Singapore's MAS urging banks to patch, on Deutsche Bank's CEO claiming the firm was "well-prepared," and on the broader pattern of central banks scrambling to assess exposure. Japan's task force represents the most concrete institutional response to date.

The Bigger Question

Mythos is the capability that triggered the White House's initial ban on Anthropic, which was then reversed in April after a direct lobbying campaign. The U.S. government decided the model was too important to keep out of federal hands. Now Japan is deciding the model is too dangerous to leave unaddressed in its financial system. Both conclusions can be true at the same time, and that tension is the defining feature of the Mythos story.

Approximately 40 organizations worldwide have access to Mythos. Asian banks have zero direct access, which means they are assessing a threat they cannot yet test against their own systems. That information asymmetry is what makes Japan's preemptive task force notable: the country is not responding to an incident. It is preparing for one that has not happened yet.

Sources: Reuters (primary), AsiaOne, Economic Times, The Straits Times. Finance Minister Katayama quotes via Reuters wire.