Nomura IR: Kikan Navi service for institutional investors breached; user names and email addresses may have leaked
Nomura IR confirmed a breach and leak at Kikan Navi, its service for institutional investors; names and email addresses may be included and the count is unknown.
Disclosed
2026-11-04
Organizations involved
1
Leaked or at risk
Unknown
Downtime
Unknown
What happened
Nomura Holdings unit Nomura Investor Relations Co., Ltd. confirmed unauthorized third-party access to the Kikan Navi system. The same day it announced emergency maintenance of its information service for institutional investors. [1] [3]
It confirmed that data had leaked. [3]
Impact
Kikan Navi sends information on companies' earnings briefings to institutional investors and analysts and helps manage attendance. The leaked data may include names and email addresses, and past registrants are also being checked. No count has been given. [1] [3]
MIR@I, its service for individual investors on the same server, was also stopped as a precaution while it checks for any access. [1] [2]
Timeline
- Detected 2026-11-02
- Disclosed 2026-11-04
- 2 days
Attack or cause
- Method
- [Intrusion]
- Impact
- [Data leak][Service outage]
- Entry point
- Unknown
Data exposed or at risk
Services hit
Organizations involved
[Breached][Critical]Tokyo, ChiyodaScientific research, professional and technical services
Nomura Investor Relations Co., Ltd.Data from Kikan Navi leaked. Names and email addresses, including those of past registrants, may be included; the count is under investigation.
Sources
- [1][Official]【重要】機関投資家・アナリスト向けIR情報提供サービス「機関Navi」への不正アクセスおよび情報漏えいについてNomura Investor Relations · 2026-11-04
- [2][News]野村系、機関投資家向けサービスで情報漏洩 不正アクセスで停止Nikkei · 2026-11-04
- [3][News]野村子会社で情報漏えい システムに不正アクセスChunichi Shimbun (Kyodo) · 2026-11-04 12:13