The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.
Reliance on components that are no longer maintained can make it difficult or impossible to fix significant bugs, vulnerabilities, or quality issues. In effect, unmaintained code can become obsolete.
This issue makes it more difficult to maintain the software, which indirectly affects security by making it more difficult or time-consuming to find and/or fix vulnerabilities. It also might make it easier to introduce vulnerabilities.