British financial authorities are accelerating reviews of systemic vulnerabilities exposed by Anthropic's Claude Mythos Preview. The Bank of England, FCA, and NCSC are mapping weaknesses across banking infrastructure—some dating back decades—ahead of formal warnings to institutions.

Wall Street's emergency discussions with Treasury Secretary Bessent mirror UK concerns. When Anthropic selectively launched Mythos last week, the $380bn AI firm reported uncovering thousands of critical flaws in foundational systems like operating browsers and operating systems.

Operational resilience takes center stage at the next CMORG meeting, where regulators and bank executives will coordinate responses. The working group's leadership includes Bank of England risk chief Duncan Mackinnon and UK Finance CEO David Postings.