> JapanHacked_
[Contained][Severity: Critical][Web app exploit]

TSS Link: about 250 support credentials and inquiry data may have leaked

An attack on its websites may have exposed about 250 support credentials and 160 inquiry records. No security problem in its products has been found.

Disclosed

2026-10-21

Organizations involved

1

Leaked or at risk

250

250

Downtime

Unknown

What happened

An attacker exploited a flaw in an extension for WordPress website-building software used by its outsourced corporate, product support, trial download and product help websites. The affected period ran from 12 June to 13 October; the intrusion was found on 13 October. [1]

Impact

About 250 registered support user IDs and login passwords may have leaked. Separately, about 160 inquiry and trial application submissions may be affected, including names, emails, phone numbers, company and department names, maintenance user IDs, messages and attachments. No deduplicated total for the two groups was published. [1]

No conclusive evidence of data theft was found, but incomplete logs prevent it being ruled out. Customer and contract data linked to IDs are held in another system, with no confirmed leak. No security problem in its products or clear resulting harm has been found. [1]

Response

It removed unauthorized administrator accounts, files and the exploited extension, and closed the known entry route. It reported to the privacy regulator on 20 October. It will contact affected users, reissue IDs and passwords, and continue investigating. [1]

Timeline

  1. Started 2026-06-12
  2. Detected 2026-10-13
  3. Disclosed 2026-10-21
  4. 131 days

Organizations involved

Sources

  1. [1][Official]当社ウェブサイトへの不正アクセスに関するお詫びとお知らせTSS Link, Inc. · 2026-10-21
  2. [2][News]WPプラグインの脆弱性悪用 ~ ティエスエスリンクのウェブサイトに不正アクセス、製品にはセキュリティ上の問題 確認されておらずScanNetSecurity · 2026-11-02 08:05