Inner source applies the working methods of open-source projects to a company’s internal software development. All developers can view the source code and submit improvement proposals. Write access remains restricted to the responsible team, which reviews and approves changes. For your ISMS, inner source offers security benefits: more eyes on the code increase the chance of finding vulnerabilities early. At the same time, you need clear rules for access control, mandatory code reviews, and handling security-critical repositories. Document in your development policy which repositories follow the inner source model.