> JapanHacked_
[Investigating][Severity: Major][Credential abuse]

Cyber Security Cloud: suspicious access with a leaked GitHub credential may have exposed customer data

A leaked employee GitHub credential was used for suspicious access to its development area; some customers’ company names, names, emails and traffic data may be exposed.

Disclosed

2026-11-12

Organizations involved

1

Leaked or at risk

Unknown

Downtime

Unknown

What happened

Cyber Security Cloud, Inc. said on 12 November that an outside organization told it one GitHub credential an employee used for work had leaked. Reviewing access logs, it found on 5 November earlier suspicious access that appears to have used that credential. Log coverage is limited, so access over the credential’s whole valid period cannot be checked. [1]

Customer company names, names, email addresses and service traffic data stored on GitHub may have been viewed or taken; who is affected is still being checked. No unauthorized access to its services or secondary harm has been found, and the services run normally. It revoked the credential and reported to the Personal Information Protection Commission and other bodies. [1]

Timeline

  1. Detected 2026-11-05
  2. Disclosed 2026-11-12
  3. 7 days

Attack or cause

Method
[Credential abuse]
Impact
[Data leak]
Entry point
Stolen credentials

Data exposed or at risk

[Name][E-mail address]

Organizations involved

Sources

  1. [1][Official]当社開発環境における情報漏えいのおそれに関するお知らせとお詫び(第一報)Cyber Security Cloud, Inc. · 2026-11-12