Vulnerability Advisory : 9Router 0.4.41 - Unauthenticated API Key Exposure via /api/usage/stats with LOW Attack Complexity

9Router through version 0.4.41 contain an unauthenticated information disclosure vulnerability that allows remote attackers to retrieve plaintext API keys for all connected AI provider accounts by sending a single unauthenticated request to the /api/usage/stats endpoint. Attackers can exploit the missing authentication middleware on the Next.js API route to obtain full API key strings alongside token counts, cost breakdowns, and request metadata, enabling unauthorized use of connected AI provider accounts, billing fraud, and quota exhaustion.