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LegalAgent AI Legal Lab

AI Legal Lab

A media by legal professionals, for legal professionals, gathering the information needed to put legal AI to full use in everyday legal work.

Data Breach & Cyberattack News

See all listed incidents

Based on official announcements by companies and organizations in Japan.As of November 7, 2026

Listed incidents in numbers

Listed incidents
278 incidents
Incidents with confirmed leaks
131 incidents
Possible leaks / investigations
127 incidents
Incidents with service / business outages
130 incidents

Gross counts of exposed information

Reference sums excluding image metadata

Information confirmed exposed
Approx. 271,831,140 reported items
Information potentially exposed
Approx. 259,552,988 reported items

Including image metadata

Information confirmed exposed
Approx. 938,231,140 reported items
Information potentially exposed
Approx. 259,552,988 reported items
Breakdown and sources

Listed incidents by month

By the latest announcement listed for each incident

  1. Apr 20262
  2. May 20265
  3. Jun 20269
  4. Jul 20267
  5. Aug 202610
  6. Sep 202638
  7. Oct 2026149
  8. Nov 202658

  1. Second notice: website partially reopened

    Possible leak

    Club TourismOnline member data / travel website

    Approx. 4.32 million records

  2. Update: three card numbers additionally confirmed

    Leak confirmed

    Prestige International (Prestige Core Solution)Business system for road-service intake and dispatch

    Up to approx. 5.5 million records (including duplicates)

  3. Third report: online store and app functions suspended

    Possible leak

    Ryohin KeikakuMUJI app and MUJI online store

    Up to approx. 27.26 million records; approx. 1.09 million MUJI Card records and others

  4. Breakdown corrected; total unchanged

    Leak confirmed

    AraraEmail delivery service “Arara Message”

    81,329,467 email addresses (deduplicated)

  5. Restart target and undetermined OEM schedule reiterated

    Leak confirmed

    Rakus Light Cloudblastmail

    All customer-contract information; non-contract information exposed for 421 contracts

Methods and coverage

See all listed incidents

Vulnerability News

See all listed vulnerabilities

Based on announcements by vendors and government agencies in Japan and abroad.As of November 7, 2026 · 66 listed

  1. Exploited

    Airbyte (Connector Builder and Manifest Server)

    CVSS 9.9 (v3.1, Airbyte (GitHub security advisory))

  2. Exploited

    PHP“php2shell”

    CVSS 9.2 (v4.0, PHP developers)

  3. Exploited

    Collabora Online - Built-in CODE Server (Nextcloud app)

    CVSS 9.2 (v4.0, Collabora)

See all listed vulnerabilities

Latest articles

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  1. Generative AI for Legal Work

    ChatGPT, Claude and Gemini: An Introduction to Choosing AI for Legal Work

    7 min
  2. Legal Outsourcing

    What Are Provisional Attachment and Provisional Disposition? Civil Provisional Remedies That Secure the Other Party's Assets and Legal Relationships Before Judgment

    9 min
  3. Contract Review

    Using Notarial Deeds with a Clause of Consent to Compulsory Execution, and When to Choose Them in Receivables Management

    10 min
  4. Contract Review

    How to Draft a Debt Acknowledgment and Repayment Agreement: Putting Installment Payments in Writing Instead of Relying on a Verbal Promise

    11 min
  5. Fundraising & Investment

    Should Founders Set Up an Asset Management Company? Legal Issues to Check Before Moving Your Shares

    8 min
  6. Fundraising & Investment

    The Angel Tax System and Fundraising: Selling Points for Individual Investors and Designing the Issuance Scheme

    10 min
  7. Fundraising & Investment

    Equity Compensation Options: How RS and RSUs Differ from Stock Options

    8 min
  8. Fundraising & Investment

    Legal Management of Subsidiaries: Group Company Rules and Internal Controls

    7 min
  9. Fundraising & Investment

    Share Buyback Procedures and Distribution Limits: Purchasing Shares from a Departing Shareholder

    8 min
  10. Startup Legal

    Amending Articles of Incorporation in Japan: Procedures, Registration and Key Provisions

    10 min

See all articles

Generative AI news

See all generative AI news

Each item links to its source.

  1. Japan / Policy & safety

    Japan adopts emergency cyber measures including AI-assisted vulnerability assessment

    View primary source: National Cybersecurity Office (official) (Open external link)

  2. Global / Research & safety

    OpenAI partners with Hacktron on security testing

    View primary source: OpenAI (official) (Open external link)

  3. Global / Research & safety

    OpenAI introduces BioBasicsBench for wet-lab data analysis

    View primary source: OpenAI (official) (Open external link)

  4. Global / Developers

    OpenAI expands agent and backend management in Codex 0.167.0

    View primary source: OpenAI (official) (Open external link)

  5. Global / Developers

    Anthropic adds background MCP tasks in Claude Code 2.1.319

    View primary source: Anthropic (official) (Open external link)

  6. Global / Research & safety

    Anthropic studies the components of agent memory

    View primary source: Anthropic (official) (Open external link)

See all generative AI news

Topics

Contract Review119 related articles

119 related articles

Contract review playbooks, clause-level checkpoints, and practical review workflows.

  1. Legal Issues in Vertical Short Dramas: Performer Agreements, Secondary Use and Overseas Distribution

    14 min

  2. English-Language Contracts for Overseas Expansion: Choosing the Governing Law and Seat of Arbitration, and Provisions Your Team Can Operate

    5 min

  3. Carbon Credits and GX Initiatives: Regulation of Environmental Claims and Points to Check in Purchase Agreements

    6 min

  4. Change of Control Clauses: Points to Check for M&A, Capital Policy and Continuity of Business Relationships

    4 min

Open theme page

Fundraising and Investment Agreements52 related articles

52 related articles

Startup financing topics including J-KISS, investment agreements, shareholders agreements, preferred shares, stock options, and capitalization.

  1. Flipping to a U.S. Holding Company: Delaware Incorporation, Shareholders and Contracts

    10 min

  2. Trust-Type vs. Paid Stock Options: Taxation and Issuance Procedures

    15 min

  3. Convertible Notes vs. J-KISS: Repayment Obligations, Maturity and Conversion Terms

    15 min

  4. J-KISS Conversion (Exercise) Procedures: A Practical Guide to Avoid Scrambling at Series A

    15 min

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M&A Legal43 related articles

43 related articles

M&A legal work including legal due diligence, SPA review, representations, indemnities, closing, business transfers, and sell-side preparation.

  1. What Are Key Person Clauses and Retention? Closing Conditions and Measures to Keep People

    9 min

  2. What Is an Earn-Out Clause? A Mechanism for Bridging Valuation Gaps in M&A and Its Dispute Risks

    12 min

  3. What Is W&I Insurance (Representations and Warranties Insurance)? Risks Covered in M&A and the Seller's Liability

    8 min

  4. How to Choose an M&A Structure: A Legal Perspective for Narrowing Down Share Acquisitions, Business Acquisitions and Reorganizations

    12 min

Open theme pageView LegalAgent M&A Support

Law Changes Calendar

See all law changes

The effective-date schedule of Japanese law changes affecting corporate practice, with effective dates, outlines and the businesses affected. The next scheduled changes are below.

Effective dateOutline and scope
2026.10.01–12.02 (by region)Revision of regional minimum wages (FY2026)Labor & HR / Businesses that employ workers
2026.11.09 (notice scheduled)Draft amendment to the Basic Guidelines on Support for Small-Scale BusinessesBusiness support & AI / Societies of commerce and industry, chambers of commerce and industry, etc., and small-scale businesses
Shimane new motor-vehicle retail minimum wage increaseEmployment and minimum wages / Covered new motor-vehicle retailers in Shimane
Digital administrative penalty hearings under the FIEA and CPA ActFinance & disclosure / Listed companies, financial instruments business operators, audit firms, etc.

See all law changes

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What is AI Legal Lab?

LegalAgent AI Legal Lab is a media site that explains, as clearly as possible, how to put generative AI to work in everyday corporate legal practice.

As a law firm for the generative-AI era that already uses generative AI to the fullest in real legal work, Legal Agent shares its hands-on know-how and practical methods in plain language.

Media coverage

  1. Representative Attorney Asato contributed an article to the September 2026 issue of Kaisha Homu A2Z (Japanese) (Open external link)
  2. Representative Attorney Asato was featured in a NewsPicks special report (Japanese) (Open external link)
  3. Representative Attorney Asato and the AI Legal Lab were featured in Houritsushoku.com's "Law x AI" roundup (Japanese) (Open external link)