5/5/26 The NHS England has temporarily moved its open-source repositories to private, citing concerns that advanced AI models like Claude Mythos Preview could accelerate the discovery of vulnerabilities in publicly available code. However, as noted in this article, experts question the effectiveness of “closing the door now,” noting that much open-source code has already been widely archived and ingested into training datasets.
The instinct to restrict access is understandable as organizations seek to understand their risks and tighten controls but we should not lose sight that security improves more often through scrutiny than through hiding.
For systems that expand in importance and complexity over time, it is not possible for a single company to anticipate every mode that may fail, use by an adversary or all operational requirements. As shared open-source foundations evolve and mature, history has shown increased value realization through reliability, implementation, orchestration, trust, and domain knowledge.
In our new era of AI, and as an eternal optimist, defenders of open source will ultimately have an advantage and organizations will benefit from this.
https://www.theregister.com/2026/05/05/nhs_to_closesource_hundreds_of_repos/