The core claim is well supported by Bloomberg Law’s "US Treasury Seeking Access to Anthropic’s Mythos to Find Flaws," which directly states that Treasury’s technology team sought access to Anthropic’s model to look for vulnerabilities and that access was being targeted as soon as that week. PANews repeats essentially the same claim and attributes it to Jinshi, aligning with the user’s wording. CoinPost also matches the substance, though it is a secondary report. Reuters does not confirm the exact 'access as early as this week' detail, but it independently supports that Treasury officials were already treating Anthropic’s Mythos as a significant cybersecurity concern. The main limitation is the absence of a fetched official Treasury or Anthropic statement, so the claim is best rated likely true rather than fully confirmed.