Government

Hiroshima City

Hiroshima City (Hiroshima, Hiroshima; Municipality) appears in 2 related cybersecurity incidents. The latest was disclosed on 2026-10-21.

Profile

Industry/type: Municipality
Location: Hiroshima, Hiroshima
Website: https://www.city.hiroshima.lg.jp/

Public figures

Residents1,167,9112026-01-01
MIC: 住民基本台帳に基づく人口、人口動態及び世帯数（令和8年1月1日現在）

Metric	Value		As of	Source
Residents	1,167,911		2026-01-01	MIC: 住民基本台帳に基づく人口、人口動態及び世帯数（令和8年1月1日現在）

Incident history

Disclosed 2026-10-21Updated 2026-10-27 19:58Aichi, Fukuoka, Hiroshima, Iwate, Kagawa, Miyagi, Nagano, Niigata, Osaka, Tochigi, Tokyo, Toyama[Investigating][Severity: Critical][Through a supplier][Major]
RAKUS Light Cloud: unauthorized access to the blastmail email delivery service
[Intrusion][Data leak][Service outage]Organizations 345
Disclosed 2026-10-13Updated 2026-10-26 12:51Aichi, Chiba, Fukuoka, Hiroshima, Hyogo, Kagoshima, Kanagawa, Oita, Okayama, Osaka, Saitama, Tochigi[Investigating][Severity: Critical][Through a supplier][Major]
Arcadia: unauthorized access to the SpeeCAN RAIDEN alert service
[Web app exploit][Data leak][Service outage]Leaked 3.1MOrganizations 28

		Incident	Role	Impact level				Methods	Impacts		Status
2026-10-21	2026-10-27 19:58	RAKUS Light Cloud: unauthorized access to the blastmail email delivery service	[Through a supplier]	[Major]	[Critical]	345 Ichinoseki City, H.I.S. Hotel Holdings Co., Ltd., HR Vision Co., Ltd., Kakaopiccoma Corp., Meitetsu World Travel, Inc., NHK Publishing, Inc., Niigata Nippo Co., Ltd., RAKUS Light Cloud Co., Ltd., Tohoku EPCO Frontier Co., Inc., Ministry of the Environment, Hiroshima City, Nagano Prefectural Government, Tokyo Metro Co., Ltd., Japan Petroleum Exploration Co., Ltd., Okazaki City, Toyama Prefectural Government, Utsunomiya City, Cells Inc., Creema Ltd., Daihatsu Motor Co., Ltd., Gyet Co., Ltd., Japan Council of Shopping Centers, Kanehara & Co., Ltd., Kyodo News, Nulab, Inc., Sasakawa Sports Foundation, Shikoku Railway Company, Takara Leben Co., Ltd., Tokamachi City, Tokyo Development Foundation for Agriculture, Forestry, and Fisheries, The Bank of Nagoya, Ltd., Sompo Japan DC Securities Inc.	Aichi, Fukuoka, Hiroshima, Iwate, Kagawa, Miyagi, Nagano, Niigata, Osaka, Tochigi, Tokyo, Toyama	[Intrusion]	[Data leak][Service outage]	Unknown	[Investigating]
2026-10-13	2026-10-26 12:51	Arcadia: unauthorized access to the SpeeCAN RAIDEN alert service	[Through a supplier]	[Major]	[Critical]	28 Arcadia, Inc., Takehara City, Aichi Prefectural Police, Chiba Prefectural Government, Fukuoka Prefectural Police, Hiroshima City, Hiroshima Prefectural Police, Hyogo Prefectural Police, Kagoshima Prefectural Police, Kanagawa Prefectural Police, Nagoya City, Oita Prefectural Government, Okayama Prefectural Police, Saitama City, Saitama Prefectural Police, Tochigi Prefectural Police, Chiba City, Fukuyama City, Hadano City, Hatsukaichi City, Oita City, Okazaki City, Yokosuka City, Ichikai Town, Kanuma City, Minamiboso City, Nasukarasuyama City, Shioya Town	Aichi, Chiba, Fukuoka, Hiroshima, Hyogo, Kagoshima, Kanagawa, Oita, Okayama, Osaka, Saitama, Tochigi	[Web app exploit]	[Data leak][Service outage]	3,136,000	[Investigating]