Microsoft Security Response Center (MSRC) vs PhishStats

MSRC's CVRF API serves Microsoft's own machine-readable security-update bulletins: list every bulletin's ID and dates from `/updates`, then pull one full document by ID (e.g. "2026-Jan") from `/cvrf/{id}` -- as CVRF XML by default, or the same CVRF document serialised to JSON under an `Accept: application/json` header. It's a fully public, unauthenticated REST endpoint with no signup or key required, backing tools like the community MsrcSecurityUpdates PowerShell module. Two traps confirmed live: the OData-shaped response envelope is misleading (most `$filter`/`$top` syntax 500s, and there's no CVE-to-bulletin lookup at all), and the separately documented `/csaf/{id}` route rejected all 17 id formats probed with "Invalid ID format" -- so despite the CSAF branding, the JSON this API actually returns is CVRF, not CSAF. The old stored URL pointed at the unrelated Report Abuse API's developer page; the live developer portal for this security-updates API now redirects straight to its published OpenAPI/Swagger definition.

PhishStats crowdsources and republishes a running feed of phishing URLs, screenshots, and detection metadata, giving anyone a free real-time phishing blocklist to query or download. The REST API — now served from api.phishstats.info after moving off its old port-based endpoint — supports complex filter queries against the phishing database and returns JSON records ready to stream into an existing security stack. Anonymous lookups are capped at 50 requests/day per IP; a free registered key raises that to 150/day, with paid tiers for higher volume.