On March 12, 2023, our production API serving 142,000 daily active users was fully exposed to the public internet for 2 hours and 17 minutes due to a misconfiguration in Deno 1.9’s built-in HTTP server and a gap in our security audit pipeline. We lost zero user data, but the near-miss cost us 120 engineering hours in remediation, $14k in emergency on-call pay, and a temporary 18% drop in user trust metrics. The vulnerability stemmed from a known (but unpatched) path traversal flaw in Deno 1.9.0’s standard library HTTP module, combined with our team’s over-reliance on overly permissive --allow-net flags and unvalidated dynamic imports in our edge runtime code.…