資さんうどんData breach / unauthorized access incident
- Occurred on
- October 1, 2021
- Announced on
- October 27, 2021
- Severity
- AFinancial and HR records — information that easily translates into monetary damage.
- Scale
- 20,000 people
- Main impact
- Personal data of approximately 20,000 current and former employees — including names, dates of birth, and phone numbers, as well as wage histories, reasons for resignation, and attendance records — may have been exposed. No fraudulent use or secondary damage has been confirmed at this time.
- Information involved
- Full nameDate of birthPhone number
- Cause / key point
- The company announced that data was exposed externally due to a configuration error by the vendor contracted to manage and operate the server (the company says it was not an unauthorized access).
- Industry
- Food & dining
- Listing / capital
- UnlistedParent company (listed holding company): すかいらーくホールディングス(3197)
The article states that 資さんうどん is under the umbrella of すかいらーくホールディングス.
- Sources
- Last updated
- October 28, 2026
Stock price reaction to the disclosureすかいらーくホールディングス・親会社(上場持株会社) 3197
Stock information is reference data based on Yahoo Finance and may be delayed. This site does not solicit or advise investment and does not guarantee the accuracy or completeness of this information. We accept no liability for any investment decision based on it.
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Written & reviewed
Reviewed byYutaro SasaoFounder & CEO, MediaLeap Inc.
CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.
Review scope: cross-checking against primary sources (official and government announcements), verifying claims stay within the facts, and checking source attribution。Last reviewed:
Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction
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Attack method classification: Misconfiguration & access-control gaps(Data left readable by anyone)
Read the Misconfiguration & access-control gaps guide and national trends →