Japan Cybersecurity in 2026: The Threats Business Leaders Need to Understand

What Japan’s 2026 threat landscape tells us

IPA’s Information Security 10 Major Threats 2026 is based on significant security incidents and attacks observed during 2025, with the organizational ranking decided through review and voting by roughly 250 researchers and corporate security practitioners. IPA — Information Security 10 Major Threats 2026

For organizations, IPA ranks the threats as follows:

Source: IPA — Information Security 10 Major Threats 2026. Threat names are translated from IPA; executive questions are editorial interpretation.

The ranking should not be interpreted as saying every company faces exactly the same risk in exactly this order.

IPA itself notes that incidents can span multiple threat categories and organizations should consider the threats in the context of their own environment. IPA — Information Security 10 Major Threats 2026

That is an important distinction.

A manufacturer, railway operator, construction company, professional-services firm and 20-person SME should not have identical cybersecurity programs.

But there are several lessons that apply widely.

1. Ransomware is a business-continuity problem

Ransomware has appeared in IPA’s organizational Top 10 for eleven consecutive years and ranks #1 in 2026. IPA — Information Security 10 Major Threats 2026

The National Police Agency recorded 226 ransomware reports involving companies and organizations in Japan during 2025. NPA — Cyber threats in 2025: full report

The more important numbers, however, concern recovery.

Among 107 2025 cases for which the NPA obtained valid responses about recovery time:

• 29 reported recovery from immediately to less than one week;
• 31 required one week to less than one month;
• 15 required one month to less than two months;
• 7 required two months or more;
• and 25 were still recovering when the information was collected. NPA — Cyber threats in 2025: full report

Cost can also be substantial.

Among 89 valid responses about investigation and recovery cost, 46 reported costs of ¥10 million or more, including five cases reporting ¥100 million or more. NPA — Cyber threats in 2025: full report

Those figures should not be interpreted as the average cost of ransomware in Japan—the NPA data represents responding cases, not every Japanese company.

But they demonstrate why the issue belongs in a business-continuity conversation.

The management question is not simply “Can we stop ransomware?”

No security system can make every attack impossible.

The more useful questions are:

• Can attackers reach internet-facing systems through an unpatched vulnerability?
• Are stolen credentials enough to gain access?
• Is MFA in place where it matters?
• Can privileged access be abused?
• Are backups isolated from the environment an attacker could encrypt?
• Have those backups actually been restored in a test?
• Who makes business decisions during an incident?
• Which system must return first?
• Can operations continue manually for a period?
• Who contacts customers, suppliers, regulators, police or other stakeholders where appropriate?

The NPA specifically recommends preparation for cyber incidents through measures including cyberattack-oriented business continuity planning, backups—including offline protection where appropriate—logging and practical exercises. It also notes that VPN devices and other internet-facing systems are common attack points when vulnerabilities, leaked credentials, weak passwords or misconfigurations are exploited. NPA — Ransomware prevention and recovery preparation

That changes ransomware from a malware discussion into a resilience discussion.

The goal is not only to prevent compromise. It is to prevent compromise from becoming prolonged business failure.

2. Your cybersecurity boundary now includes your supply chain

IPA ranks attacks against supply chains and outsourced providers #2 for 2026, the eighth consecutive year that the category has appeared in the organizational Top 10. IPA — Information Security 10 Major Threats 2026

This matters because modern businesses depend on:

• suppliers,
• subcontractors,
• IT providers,
• cloud services,
• software vendors,
• maintenance companies,
• professional advisers,
• logistics providers,
• group companies,
• and other external organizations.

A business can invest heavily in its own cybersecurity and still suffer disruption through an organization it relies upon.

IPA’s 2024 SME security study surveyed 4,191 Japanese SMEs and specifically highlighted how insufficient security at a company within a supply chain can affect the company itself, interrupt products or services, expose important information, affect business partners, or provide a foothold for attacks against another organization. IPA — FY2024 SME information-security survey (4,191 SMEs)

That means supplier management can no longer be purely about:

• price,
• quality,
• delivery,
• and contractual performance.

Cybersecurity increasingly becomes another dependency to understand.

This does not mean treating every supplier identically

A stationery supplier and a managed IT provider normally create very different cyber risks.

A useful approach is to understand:

• What does this party access?
• What systems connect to it?
• What information does it hold?
• Could its failure interrupt operations?
• Could it access our network?
• Could compromise of this provider become compromise of us?

Security requirements can then be proportional to the relationship.

Japan’s new SCS framework reflects this shift

In March 2026, METI and the National Cybersecurity Office published the framework for Japan’s new Supply Chain Security Evaluation System, or SCS.

The framework is intended to make expected cybersecurity measures easier to communicate between customers and suppliers and make suppliers’ implementation status more visible. Company applications for ★3 and ★4 are currently targeted around the end of FY2026 (January–March 2027); IPA’s FAQ describes an operational start around March 2027. Timing and details remain subject to official updates. IPA — SCS operating schedule and FAQ

An important clarification:

SCS is voluntary.

METI explicitly states that the scheme itself does not impose a regulation requiring companies to obtain a star rating or universally prohibit trade with unrated firms. Requirements can instead arise through business relationships and contracts between customers and suppliers. METI / NCO — Supply Chain Security Evaluation System (SCS)

For business leaders today, the larger lesson is simpler:

Cybersecurity expectations are increasingly travelling through the supply chain.

3. AI has become a cybersecurity governance issue

One of the most significant changes in IPA’s 2026 ranking is the introduction of:

“Cyber risks associated with the use of AI”

at #3, on its first appearance in the organizational ranking. IPA — Information Security 10 Major Threats 2026

That does not mean businesses should stop using AI.

It means AI adoption has become large enough that security governance cannot be separated from AI governance.

Consider everyday questions:

• Can an employee paste confidential information into a public AI service?
• Which AI services are approved?
• Can an AI system access internal documents?
• Can it access customer data?
• Can an AI agent invoke another enterprise system?
• Can it send messages or create records?
• Who approves those permissions?
• What happens if AI-generated information is incorrect?
• Are important AI-assisted actions logged?
• Is a human required before a consequential action?

The security problem therefore changes as AI moves from:

assistant

to:

participant in a business process

to:

actor capable of using tools and systems.

A company does not need to prohibit AI to manage this risk.

It needs to define:

data boundaries, access boundaries, authority boundaries and accountability.

That is why AI security should be considered together with enterprise AI governance rather than treated only as another employee-awareness topic.

For practical design, see governed enterprise AI and human-in-the-loop governance. Unapproved or shadow AI use also needs clear rules for data and access.

4. Basic vulnerabilities still matter—even while technology becomes more sophisticated

AI may be new, but one of Japan’s other leading threats is very familiar.

IPA ranks attacks exploiting system vulnerabilities #4. IPA — Information Security 10 Major Threats 2026

The National Police Agency’s ransomware guidance notes that attackers frequently target exposed systems such as VPN devices using:

• unpatched vulnerabilities,
• leaked credentials,
• weak passwords,
• and configuration problems. NPA — Ransomware prevention and recovery preparation

This creates an important contrast.

Companies can discuss:

• AI governance,
• zero trust,
• advanced analytics,
• SOC modernization,
• and sophisticated detection,

while still carrying risk from:

• an old remote-access appliance,
• an administrator account with excessive privileges,
• a forgotten SaaS account,
• an internet-facing system nobody owns,
• or a critical patch that remained unapplied.

Modern security therefore still depends on basic operational discipline.

Leaders do not need to know every CVE

But someone in the organization needs to be able to answer:

• What internet-facing assets do we have?
• Who owns them?
• Which vulnerabilities are critical to us?
• How quickly do we address them?
• Which systems cannot easily be patched?
• What compensating controls exist?
• What happens when a vendor no longer supports a product?

This is especially important in manufacturing, infrastructure and organizations with long-lived systems.

5. Confidential data remains a target

IPA places targeted attacks against confidential information at #5. IPA — Information Security 10 Major Threats 2026

For different businesses, the valuable information may be completely different:

• product designs,
• construction plans,
• customer information,
• technical drawings,
• pricing,
• financial forecasts,
• contract information,
• employee data,
• credentials,
• M&A information,
• source code,
• manufacturing know-how,
• or strategic plans.

The security question therefore should not start with:

“What data do hackers want?”

Start with:

“Which information would cause serious damage if stolen, altered, destroyed or made unavailable?”

Once the business can answer that, security priorities become much easier to define.

6. Cyber risk does not come from only one type of attacker

The lower half of IPA’s Top 10 contains an important reminder.

Japan’s organizations must also consider:

• geopolitically motivated cyber activity,
• insider threats,
• remote-work attacks,
• DDoS,
• and business email compromise. IPA — Information Security 10 Major Threats 2026

These require different controls.

A phishing-resistant authentication strategy does not solve DDoS.

DDoS protection does not stop a fraudulent payment approved after a convincing executive impersonation.

An EDR agent does not automatically prevent excessive employee access.

A security-awareness program does not patch a vulnerable VPN device.

This is why cybersecurity should not be managed as a collection of individual products.

It should begin with business risk and attack paths.

7. Cybersecurity is increasingly a management responsibility

Japan’s Cybersecurity Management Guidelines Ver. 3.0, published by METI and IPA, are written for executives of large companies and SMEs (excluding very small businesses) that supply IT systems or services, or rely on IT for their business strategy.

METI describes management involvement as necessary for organizations to implement cybersecurity measures before attacks or incidents occur. METI / IPA — Cybersecurity Management Guidelines Ver. 3.0

This does not mean CEOs need to configure firewalls.

It means management should determine:

• what must be protected;
• how much risk the organization can accept;
• who owns cybersecurity;
• how sufficient resources are provided;
• how important suppliers are treated;
• how incidents are escalated;
• and how recovery priorities align with the business.

That is governance.

Technology implements part of it.

The management guidelines are guidance, not legislation or a requirement to adopt this article’s models. IPA — Management-guideline practice navigation

8. Software suppliers are also being asked to take greater responsibility

Cybersecurity responsibility is changing on the supplier side too.

On 31 March 2026, METI and the National Cybersecurity Office finalized the Guidelines on the Roles Expected of Cyber Infrastructure Providers.

The guidance covers organizations that develop, provide or operate software—including software services, cloud services, embedded software and software associated with IT, OT and IoT equipment.

It emphasizes improving resilience across the software supply chain and reflects ideas such as secure by design and secure by default. Customers can also use the guidance as a reference when evaluating software suppliers. METI / NCO — Roles Expected of Cyber Infrastructure Providers

For business leaders, the practical lesson is:

Buying technology does not transfer all cybersecurity responsibility to the vendor—and selling technology increasingly carries security responsibilities of its own.

The guidance is a reference for providers and customers; the article does not treat every recommendation as a universal legal duty.

9. Japan also has a cybersecurity talent constraint

Technology alone cannot solve cybersecurity if organizations cannot find or develop the people needed to manage it.

METI’s 2025 cybersecurity talent report cites a private estimate, from the ISC2 Cybersecurity Workforce Study 2023, that Japan faces a shortage of approximately 110,000 cybersecurity professionals. METI — Final report on developing cybersecurity talent

METI is therefore pursuing measures to increase both the quantity and quality of cybersecurity talent.

The wording matters:

110,000 is an estimate cited by METI from a private survey. It is not a headcount independently calculated by METI.

The practical implication is nevertheless significant.

Not every company can or should build every cybersecurity specialty internally.

Many organizations will need some combination of:

• internal security ownership;
• IT staff;
• business/process owners;
• specialist security providers;
• technology vendors;
• and external advisers.

The strategic question is not:

“Should cybersecurity be internal or outsourced?”

It is:

“Which cybersecurity responsibilities must we own internally, and where should we use specialist external capability?”

10. Security maturity is not measured by how many security products you own

IPA’s SME research illustrates an important gap.

Among the 4,191 SMEs surveyed:

• 73.0% reported full or partial implementation of keeping operating systems and software current;
• 71.4% reported full or partial implementation of antivirus measures, including keeping virus definitions current.

But organizational measures were much less common:

• only 39.8% reported having at least some preparation such as an emergency structure or procedure for security incidents;
• 39.2% had at least partially formalized security measures as rules communicated to employees;
• and 37.9% reported full or partial implementation of a mechanism for learning about new threats and sharing countermeasures internally. IPA — FY2024 SME information-security survey (4,191 SMEs)

These are SME findings and should not be generalized to every Japanese company.

But they illustrate a broader principle:

Buying security technology and building a security operating model are different things.

An organization may own good products and still struggle when:

• nobody knows who declares an incident;
• an executive cannot be reached;
• a supplier is affected;
• backup restoration fails;
• a critical employee is absent;
• legal and communications teams are not included;
• or nobody knows which system should be restored first.

Cyber resilience requires process as well as technology.

11. Supply-chain security needs a process, not just a questionnaire

Imagine a large company sends its suppliers an annual security spreadsheet.

Supplier completes it.

Someone stores it in a folder.

Nothing happens for twelve months.

That may satisfy an administrative task.

It does not necessarily manage supplier risk.

A more mature process could be:

1. Identify the supplier
2. Assess business importance and access
3. Select security requirements
4. Collect evidence
5. Review risk
6. If gaps exist: remediate, verify or escalate before approval; otherwise approve
7. Monitor significant changes
8. Reassess when appropriate

That distinction becomes increasingly important as Japanese companies prepare for SCS and stronger supply-chain security expectations.

What should management ask in 2026?

Executives do not need to become security engineers.

But they should be able to obtain credible answers to questions like these:

This is not a regulatory checklist.

It is a management conversation starter.

A practical 90-day starting point

An organization does not have to solve every cybersecurity problem at once.

A practical first 90 days could look like this.

Days 1–30 — Understand

Identify:

• critical business processes;
• critical systems and data;
• internet-facing services;
• privileged access;
• key suppliers;
• recovery dependencies;
• existing policies;
• incident roles;
• and current AI usage.

The goal is visibility.

Days 31–60 — Prioritize

Address the most consequential gaps.

Depending on the organization, that could include:

• critical patching;
• MFA;
• old accounts;
• privileged access;
• backup isolation;
• recovery testing;
• external exposure;
• supplier-risk classification;
• or AI-use rules.

The goal is not “perfect security.”

It is reducing the most important risks first.

Days 61–90 — Test

• Run an incident exercise.
• Test a real restoration.
• Simulate an unavailable system.
• Walk through a supplier compromise.
• Verify the escalation tree.
• Confirm who has decision authority.
• Produce a prioritized roadmap for the next phase.

The goal is to discover weaknesses before a real attacker discovers them for you.

This 90-day structure is an illustrative Axton editorial model, not an IPA, METI, NPA or NCO framework. It does not promise that cybersecurity transformation can be completed in 90 days.

Prevention, resilience and governance

Strong cybersecurity needs all six.

A business that invests only in prevention may still be unprepared for recovery.

A business that writes policies but never tests them may have governance on paper but not in practice.

Where Axton Group can support

Axton Group LTD Japan’s cybersecurity approach is built around understanding the business context first.

Depending on the engagement and agreed scope, areas of support may include:

• cyber-risk and security-readiness assessment;
• asset, access and dependency review;
• ransomware and cyber-resilience preparation;
• security-governance and policy support;
• supply-chain and third-party security;
• SCS readiness and gap analysis;
• AI-security and governance discussions;
• incident-readiness planning;
• remediation planning;
• and workflow design around security processes.

Where highly specialized capabilities are required—for example deep offensive-security testing, specialist digital forensics, 24/7 monitoring or specialized OT assessment—appropriate qualified specialists or delivery partners may be required depending on project scope.

That distinction matters.

Good cybersecurity begins with accurately understanding both risk and capability.

Explore Axton’s cybersecurity support

Cybersecurity and digital transformation should not be separate conversations

The more businesses connect:

• ERP,
• CRM,
• cloud services,
• AI,
• supplier portals,
• customer platforms,
• factories,
• remote workers,
• APIs,
• and external partners,

the more cybersecurity becomes part of digital architecture.

Security added only after implementation often becomes:

• a restriction;
• an emergency;
• or an expensive remediation exercise.

A better approach is:

1. Business need
2. Architecture
3. Data & access
4. Security requirements
5. Workflow & controls
6. Implementation
7. Monitoring & improvement

This is especially important when automation or AI begins taking action across multiple enterprise systems.

Security should enable digital transformation to move safely—not simply tell it to stop.

Enterprise Automation service connects this discussion to digital-process design.

The cybersecurity question for 2026

Japan’s cyber threat environment contains both old and new problems.

• Ransomware remains at the top.
• Supply-chain attacks remain persistent.
• AI introduces new questions.
• Unpatched systems still matter.
• Sensitive information is still targeted.
• Remote access, fraud, insiders, DDoS and geopolitical risks remain relevant.

Meanwhile, Japanese policy is moving toward stronger supply-chain security, greater management involvement, more explicit software-provider responsibility and continued development of cybersecurity talent. METI / NCO — Roles Expected of Cyber Infrastructure Providers

The conclusion is not that every business needs every security product.

It is that every business needs to understand:

what it depends on, what would hurt most if compromised, who is responsible, and how the organization would continue operating when prevention fails.

That is where cybersecurity becomes cyber resilience.

And in 2026, that is increasingly a management issue—not merely an IT issue.