About
OpenPostern started as a tool to answer one question: how do you know if a vendor you trust has been compromised?
The problem
Small businesses rely on dozens of SaaS vendors: payroll, accounting, CRM, communications, storage. Each one holds data. Each one is a potential entry point. But unlike large enterprises, small businesses have no dedicated security team to track vendor posture, read CVE disclosures, or monitor certificate expiry. They simply trust and move on.
A single compromised vendor can expose PII, financial data, or business operations. Security teams exist at large companies to catch these signals early. Everyone else was flying blind.
What we built
OpenPostern monitors vendor CVE exposure, CISA Known Exploited Vulnerabilities, SSL/TLS certificate health, and DNS security configuration. Scores update automatically. Alerts fire when something changes. No security expertise required.
Our principles
Signal over noise
Every alert represents a real, measurable change in risk posture. No vanity metrics.
Transparency
The scoring methodology is public. You can read exactly how every score is calculated.
Small business first
Designed for teams of 5 to 500 who share one security budget among many priorities.
Contact
General inquiries
hello@openpostern.comSecurity concerns
security@openpostern.com