INSPECTING ARCHIVED INTELLIGENCE (OUTDATED VERSION).

Burger King Japan Experiences Data Breach Impacting 11 Million Customers

| 2026-10-16 14:04 HIGH LOW DATA BREACH
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Executive Summary
AI-generated
On October 2-7, 2026, Burger King Japan's membership system was accessed by attackers, exposing the personal data of approximately 11.18 million app users and official app members. The company has not identified the attackers or explained how they gained access to the system managing customer membership information. The compromised data includes membership IDs, email addresses, names in Japanese characters and kana, phone numbers, dates of birth, gender, prefecture of residence, and membership registration type. Burger King Japan is working with external security specialists to determine the cause of the unauthorized access and has introduced temporary countermeasures, established an incident response team, and reported the breach to Japan's Personal Information Protection Commission. The company has confirmed that customer membership information from the official app was leaked externally following unauthorized access by a third party, but the investigation is ongoing and it remains unclear what specific circumstances led to the intrusion.
Technical Mitigations AI-generated
• User Training (ATT&CK mitigation for Impersonation): Train users to be aware of impersonation tricks and how to counter them, for example confirming incoming requests through an independent platform like a phone call or in- • Threat Intelligence Program (ATT&CK mitigation for Impersonation): Threat intelligence helps defenders and users be aware of and defend against common lures and active campaigns that have been used for impersonation. • Audit (ATT&CK mitigation for Phishing): Perform audits or scans of systems, permissions, insecure software, insecure configurations, etc. • Network Intrusion Prevention (ATT&CK mitigation for Phishing): Network intrusion prevention systems and systems designed to scan and remove malicious email attachments or links can be used to block activity. • Account Use Policies (ATT&CK mitigation for Social Engineering): Adds verification for helpdesk resets, approvals, and app consents commonly targeted by impersonation.
Intelligence Metadata
Actors / Malware / CVEs / Campaigns
Target & Sectors
JP
Incident Timeline
‎October 2
Unauthorized access to the system managing customer membership information occurred at Burger King Japan from October 2 through October 7, 2026.
target_region Japan
Burger King Japan, the company operating the fast-food chain in the country, said attackers accessed the system managing customer membership information between October 2 and October 7, 2026.
‎October 7, 2026
Attackers accessed the system managing customer membership information of Burger King Japan between October 2 and October 7, 2026.
target_region Japan
Burger King Japan, the company operating the fast-food chain in the country, said attackers accessed the system managing customer membership information between October 2 and October 7, 2026.
organisation BK
BK Japan says it’s working with external security specialists to determine the cause.
organisation SecurityAffairs
Follow me on Twitter:  @securityaffairs  and  Facebook  and  Mastodon Pierluigi Paganini ( SecurityAffairs  – hacking, Burger King Japan)
organisation Burger King
Attackers can use them to craft convincing phishing emails, text messages, or phone calls that refer to a customer’s real identity and relationship with Burger King.
‎October 7
Unauthorized access to Burger King Japan's systems occurred from October 2 through October 7.
‎October 13
Unauthorized access to Burger King Japan's systems occurred from October 2 through October 7, resulting in a data breach that was confirmed on October 13.
‎October 15
Burger King Japan disclosed a data breach on October 15, confirming unauthorized access to customer data two days prior.
tactic Data Leak
The company disclosed the incident on October 15, after discovering the data leak two days earlier.
‎2026/10/16
Threat actors accessed Burger King Japan's membership system, exposing the personal data of approximately 11.18 million app users.
organisation Burger King Japan Data Breach
Burger King Japan Data Breach Impacted 11 Million Customers.
victims 11 Customers
Burger King Japan Data Breach Impacted 11 Million Customers.
Burger King Japan Data Breach Impacted 11 Million Customers Burger King Japan disclosed a breach exposing 11.18 million app users’ personal data after attackers accessed its membership system in early October.
victims 11.18 app users
Burger King Japan Data Breach Impacted 11 Million Customers Burger King Japan disclosed a breach exposing 11.18 million app users’ personal data after attackers accessed its membership system in early October.
organisation Burger King Japan
Burger King Japan has disclosed a data breach that exposed the personal information of approximately 11.18 million official app members.
data_breach 11.18 app members
Burger King Japan has disclosed a data breach that exposed the personal information of approximately 11.18 million official app members.
Tactical Metrics
Metrics
victims
11,000,000
Customers
Burger King Japan Data Breach Impacted 11 Million Customers.
Burger King Japan Data Breach Impacted 11 Million Customers Burger King Japan disclosed a breach exposing 11.18 million app users’ personal data after attackers accessed its membership system in early October.
Metrics
victims
11,180,000
App Users
Burger King Japan Data Breach Impacted 11 Million Customers Burger King Japan disclosed a breach exposing 11.18 million app users’ personal data after attackers accessed its membership system in early October.
Metrics
data_breach
11,180,000
App Members
Burger King Japan has disclosed a data breach that exposed the personal information of approximately 11.18 million official app members.
Intelligence Sources
Security Affairs 2026-10-16