Anthropic Reports Leak of Claude Account Information for Over 100 South Korean Companies

on November 9, according to Yonhap News Agency, US-based Anthropic has notified the Korea Personal Information Protection Commission that over 100 Korean corporate account details for its generative AI service Claude were leaked. The commission stated on November 9 that Anthropic reported the incident on October 31, and it is currently in a preliminary review phase without a formal investigation having been launched.

According to earlier reports from The Washington Post, US cybersecurity startup Cathedral accessed Anthropic’s internal systems by exploiting a vulnerability in third-party office software. Anthropic researcher Lydia Hallie said on X that Cathedral gained unauthorized access to account information including names, email addresses, and subscription plans, but did not obtain prompts, outputs, or payment information. The company disabled the affected systems and patched the vulnerability on the day it became aware of the breach.