This study investigates the security implications of reusing code snippets of Stack Overflow in open-source software projects. We present novel framework that proactively identifies and mitigates security risks associated with outdated Stack Overflow code snippets. Our approach combines static code analysis techniques, continuous monitoring of Stack Overflow post changes, and an automated developer notification system. We analysed 1.5 million code snippets from Stack Overflow approximately across 5000 popular open-source GitHub projects, focusing on programming codes. Our findings reveal that a significant number of reused snippets become outdated over time, with developers often missing critical security updates made to the original Stack Overflow posts. We demonstrate the effectiveness of our framework in detecting potential vulnerabilities and alerting developers to security-relevant updates in reused code. The study highlights the need for continuous monitoring of community-sourced code and proposes solutions to ensure its secure integration in software development practices. Our work contributes to the broader understanding of software supply chain security and the evolving nature of code reuse in the open-source ecosystem.