End-of-support is a vendor deadline after which a product no longer receives security fixes, feature updates, or official technical help. In practice, the software may keep running, but newly discovered vulnerabilities will usually remain unpatched. That makes end-of-support an important security milestone rather than just a procurement issue.
In cyber security, unsupported systems are attractive targets because attackers know flaws are more likely to stay exploitable. Defenders use end-of-support dates to drive patching, replacement, segmentation, and risk reviews. If an upgrade is delayed, teams may reduce exposure with stronger monitoring, strict access controls, and isolation of the legacy system. For enterprise platforms such as ERP, end-of-support can also affect compliance and incident response, because outdated software may no longer meet organizational security baselines or audit expectations.