神奈川県消防保安課（事業者へのメール誤送信）Data breach / unauthorized access incident
- Occurred on
- October 13, 2026
- Announced on
- October 14, 2026
- Severity
- CLimited data such as email addresses and identifiers.
- Scale
- 55 records
- Main impact
- An email sent by 神奈川県消防保安課 to 55 liquefied petroleum gas sales operators was sent without using BCC, allowing recipients to view each other’s email addresses. No actual third-party misuse is reported.
- Information involved
- Email address
- Cause / key point
- This was caused by sending the email without using BCC. The prefecture says it will enforce BCC use, require pre-send checks by multiple people, and conduct staff training.
- Industry
- Government & municipal
- Listing / capital
- Government / public body
Sent by a department of a local public authority
- Sources
- Last updated
- October 20, 2026
Is this incident worth paying attention to?
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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: Misdirected sending & disclosure (human error)(Leaks caused by wrong recipients or exposure settings)
Read the Misdirected sending & disclosure (human error) guide and national trends →