White House orders Anthropic to cut foreign access to Claude Mythos after security concerns
The U.S. administration directed Anthropic to revoke access to its Claude Mythos and Fable 5 models for all non-U.S. users, citing worries about potential ties between South Korean telecom SK Telecom and China and recent vulnerability reports.
The White House instructed Anthropic to discontinue access to its Claude Mythos and the highly restricted Fable 5 version for all foreign nationals after concerns were raised about the South Korean telecom operator SK Telecom’s alleged connections to China and a vulnerability report from Amazon.
U.S. officials, who had been reviewing export controls on Anthropic’s most advanced AI technology, said the company’s decision to grant SK Telecom access to Mythos heightened security worries. Amazon researchers reported that some guardrails in Fable 5 could be bypassed, potentially exposing the model’s cyber-capability functions. Anthropic and independent security experts responded that such risks are not unique to Claude.
"The letter from the government demanding that Anthropic restrict access to Claude Mythos and Fable 5 solely to U.S. nationals does not mention the Korean company or China," a source close to Anthropic said.
Anthropic, which runs a limited early-access program called Project Glasswing, had included SK Telecom among roughly 150 organizations receiving the model after expanding the program in collaboration with external experts and U.S. authorities. The telecom firm, which has invested in Anthropic and partnered on a telecommunications-focused AI model, complied with the order and its access was revoked.
SK Telecom, part of the larger SK Group, has a modest financial presence in China, reporting about $1.9 million in revenue and employing seven staff there in 2024. The company’s historical involvement includes a joint venture with China Unicom that began in 2004 and was largely unwound by 2009, though a small investment remains.
The administration’s action reflects broader U.S. efforts to limit technology transfers that could benefit Chinese entities deemed linked to military or intelligence activities. Anthropic declined to comment, and the White House and SK Telecom did not immediately respond to requests for comment.