Basel utility IWB: ~40,000 customer records exfiltrated in a breach of a third-party service provider

Industrielle Werke Basel (IWB) (the canton-owned Basel multi-utility supplying electricity, gas, water, district heating and telecom/fibre) disclosed on 15 July 2026 that an external service provider it uses was compromised and roughly 40,000 customer records were exfiltrated from the provider's environment (Netzwoche, 2026-07-15). The stolen data comprises customer names and addresses plus technical smart-meter attributes (meter serial numbers and installation characteristics); IWB states that email addresses, phone numbers, energy-consumption data and billing/payment data were not part of the exposure, so no consumption-pattern inference is possible from what was taken (SwissCybersecurity.net, 2026-07-15). IWB's own IT and OT/grid systems were unaffected and energy/water supply continuity was not disrupted; the compromise is scoped to the provider's systems and the customer-data feed IWB shares with it (Netzwoche, 2026-07-15). The provider detected and notified IWB, which audited access, reviewed logs and pre-emptively restricted its data exchange with the affected provider; the Basel-Stadt cantonal data protection officer assessed the misuse risk as low (Watson.ch, 2026-07-15). No provider name, threat-actor claim or initial-access vector has been disclosed, and no matching leak-site listing was found for Switzerland in-window.