> JapanHacked_
[Contained][Severity: Critical][Intrusion]

teket: member data leak confirmed; all electronic-ticket services suspended

Unauthorized access exposed member names, email addresses and other ticketing data. The count remains under investigation and all services are suspended.

Disclosed

2026-11-08

Organizations involved

31

Leaked or at risk

Unknown

Downtime

Unknown

Confirmed exposure and suspension

After identifying likely unauthorized access on 5 November, teket stopped all services at 20:30 and blocked access. External exposure of member information was confirmed on 6 November. Fields include names and email addresses, plus birth dates, ages, gender, addresses, phone numbers, ticket-issuance codes and organizer serial codes where registered or purchased. The affected count is still being assessed. [1]

Purchased QR tickets cannot be displayed; organizer login and QR admission scanning are unavailable. Admission guidance uses purchase-confirmation emails or purchaser names while investigation and restoration work continue. No new intrusion, expanding damage, unauthorized logins or misuse of exposed data has been confirmed. [1]

Kyoto City said teket reported a leak of participant data for Kyoto City Arts and Culture Association. Kyoto Symphony Orchestra and Kyoto East Cultural Hall also used teket for some events, but the city said the operator had not reported a leak for them and was checking. [30]

Kiyose City said teket reported that some information held for Kiyose Keyaki Hall event customers leaked externally. The city did not give a count or fields. [31]

Kurashiki City reported possible exposure of purchasers for two events at Tamashima Citizens Exchange Center, including past purchases. Potential fields include names, addresses, email and phone; the count is unknown. [32]

Client notices

Client/operator
Published scope/status
Kanagawa Prefecture
Dragon used teket for the Re-Koten project. Member data and ticket codes may be exposed; scope and count remain under review.[2]
Administrative Agency for Osaka City Museums
Osaka Museum of History events held from 19 July onward may be affected. Inclusion of attendees is not established; museum-system intrusion is not confirmed.[3]
Okazaki City
Potential scope includes tickets for the 2023 Ieyasu parade. Inclusion of the city’s users, fields and count are under investigation.[4]
Ichinomiya City
Possible exposure concerns the 48th fire-brigade band concert: names, age, gender, addresses, phones, email and ticket data. Sales switched to paper tickets.[5]
Hino City
Investigating whether Tanizo Family Concert purchasers are included; specific scope and headcount are not established.[6]
Hachioji City
Used teket for the Tanizo Family Concert; customer-data impact and the affected count are being checked.[7]
Tokyo Sports and Culture Foundation
Used for Smile Sports and related applications. Exposure scope is under review and booking methods are changing.[8]
Sapporo Lifelong Learning Promotion Foundation
Possible exposure concerns Sapporo Science Center event purchasers; scope remains under investigation.[9]
Tsukuba Science Expo Memorial Foundation
Used for Tsukuba Expo Center events; customer data may be affected. Alternative booking is provided during suspension.[10]
Kyoto City Arts and Culture Association
Possible exposure concerns participants in specified Kyoto Art Center workshops; individual scope is being checked.[11]
Ishikawa Prefectural Music and Culture Promotion Corporation
Concert users’ data may be affected. Sales and QR display are unavailable; admission uses confirmation emails or purchaser names.[12]
Chuo University
Used for AI/data-science seminars. The university warns of possible exposure and provides alternative registration arrangements.[13]
Musashino Ongaku Gakuen
Used for concert ticketing. The college reports the exposure notice and alternate sales/admission arrangements.[14]
Kunitachi College of Music
Inclusion of its concert purchasers is not yet confirmed. The college is checking scope, including comparison with its own data.[15]
Japan Philharmonic Orchestra
Checking the impact on its teket purchasers; no specific affected count is given.[16]
Nagoya Philharmonic Orchestra
Reports suspended teket sales for specified concerts. Other channels remain available; this notice gives no orchestra-specific exposure count.[17]
Pacific Philharmonia Tokyo
Warns concert purchasers about the exposure, redirects sales and registration, and cannot look up bookings during the outage.[18]
LF Concert
Provides alternative ticket sales and admission checks during teket’s outage. Specific exposure of its own customer data is not disclosed.[19]
Yokohama DeNA BayStars Baseball Club, Inc.
Reports possible event-purchaser exposure and explains event/admission arrangements. Yokohama Stadium separately handles stadium-tour sales.[20]
Tokyo Sunbeams
Warns of the teket outage and suspicious contacts; no team-specific exposure fields or count are disclosed.[21]
Japan Amateur Radio League
Used teket for Ham Fair admission. The provider is investigating purchaser-data impact; no count is disclosed.[22]
Tokyo Reiki Kogyo Co., Ltd.
Checking with teket whether its event purchasers are affected. This is not a confirmed intrusion into the company’s own systems.[23]

Sesion Suginami and Chieria

Sesion Suginami’s Tokyu Community–Tokyu Bunkamura–Kyowa Sangyo management joint venture reports possible exposure of 452 attendee entries for events from July 2024 onward, with names, email, birth dates, age, gender, addresses and phones. The duplicate-inclusive count is not a unique headcount and is not multiplied across venture members. [24]

Chieria reports that it used teket for Yurikago Concert tickets and was told some entrusted information had leaked. It has the same operator as Sapporo Science Center, so no duplicate legal entity is created. No count is stated. [25]

FC Fujizakura Yamanashi also reports possible inclusion of its ticket purchasers; its specific customers, fields and headcount remain undetermined. [26]

Fukushima used teket for its sake/miso/soy-sauce festivals in March 2025 and June 2026. Hockey Japan League also warns that match purchasers may be included. Neither gives an organization-specific exposed count. Orchestra Ensemble Kanazawa’s operator provides admission using purchase-confirmation emails and related checks. [27] [28] [29]

Kyoto Modern Architecture Festival’s committee is checking the scope for passport and guided-tour purchasers; it has not established event-specific counts or fields. Office meSquare also warns that online-seminar applicants may be included, with new registration and archive viewing stopped. It excludes its offline seminars, which did not use teket. Neither establishes every supplier-wide field as exposed for its own events. [33] [34]

Timeline

  1. Detected 2026-11-05
  2. Disclosed 2026-11-08
  3. 3 days

Attack or cause

Method
[Intrusion]
Impact
[Data leak][Service outage]
Entry point
Unknown

Data exposed or at risk

[Name][E-mail address][Phone number][Postal address][Date of birth][Gender][Purchase history]

Supply chain

teket Inc.

[Breached]

Organizations listed on this site
31

Services hit

Organizations involved

Open in organization search

Sources

  1. [1][Official]【重要】不正アクセスによる情報流出に関するお詫びとお知らせ（第一報）teket · 2026-11-08
  2. [2][Official]「カナガワ　リ・古典プロジェクト事業」の委託事業者が利用する電子チケット販売・管理サービスへの不正アクセスによる情報流出の可能性について - 神奈川県ホームページKanagawa Prefecture · 2026-11-09
  3. [3][Official]大阪市：報道発表資料　大阪歴史博物館において利用する電子チケット販売・管理サービスでの情報漏えいの可能性について（第1報）Osaka City · 2026-11-09 17:00
  4. [4][Official]「teket」の会員情報等を管理するシステムへの不正アクセスにより個人情報漏えいの可能性があることが判明しました。｜岡崎市公式ホームページOkazaki City · 2026-11-09
  5. [5][Official]2026年11月9日報道発表　第48回一宮市消防音楽隊定期演奏会電子チケット販売・管理サービス委託業者への不正アクセスによる個人情報漏洩について｜一宮市Ichinomiya City · 2026-11-09
  6. [6][Official]チケット販売サービス「teket」における個人情報流出について｜日野市公式ホームページHino City · 2026-11-09
  7. [7][Official]チケット販売サービス「teket」における個人情報流出について／八王子市子育て応援サイトHachioji City · 2026-11-09
  8. [8][Official]スマイルスポーツ事業が利用している電子チケット販売サービス「teket」における個人情報漏えいについて（初報） | お知らせ一覧 | 公益財団法人 東京都スポーツ文化事業団Tokyo Sports and Culture Foundation · 2026-11-08 18:35
  9. [9][Official]電子チケット販売・管理サービス『teket』への不正アクセスによる情報流出に関するお詫びとお知らせ|お知らせ | 札幌市青少年科学館Sapporo Science Center · 2026-11-08
  10. [10][Official]電子チケット販売・管理サービス『teket』への不正アクセスによる情報流出に関するお詫びとお知らせ | つくばエキスポセンターTsukuba Expo Center · 2026-11-08