Network‑AI before version 5.15.2 contains an origin validation error in the McpSseServer._handleRequest routine that improperly mirrors any encountered Origin header containing "localhost" into the Access‑Control‑Allow‑Origin response header. This flaw permits a foreign web page that a victim visits locally to request authenticated endpoints such as "/health" from the server and receive the response without authorization, effectively bypassing same‑origin enforcement. The weakness is a classic CORS misconfiguration (CWE‑346).

Any deployment of Jovancoding Network‑AI using npm package "network‑ai" older than version 5.15.2 is affected. Users running the software on interfaces that bind to a non‑loopback address will be subject to the fault in the CORS handling logic.

The publicly disclosed CVSS score is 2.3, indicating low overall severity. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog, suggesting that exploitation has not been observed in the wild or is unlikely to be actively weaponized. Attackers would need to host a page that the victim visits, with a localhost Origin header, and the victim’s browser must accept the mirrored header. While the technical barrier is modest, the lack of an exposed authentication mechanism keeps the risk of sensitive data exposure low. Nonetheless, accidental navigation to a page with the simplified Origin could expose health or status information to an attacker. Overall, the risk is moderate given the potential for data leakage but mitigated by low exploitation probability.