Windows KB Patch Lookup
Release notes, affected OS builds, CVE severity, and known issues/mitigations — pulled live from Microsoft.
Single lookup
Bulk lookup
CVE lookup
Monthly digest
Results are cached for a day.
Runs lookups in parallel. Good for triaging a whole Patch Tuesday batch at once.
Goes the other direction: paste a CVE from a scanner report and find which KB fixes it.
Everything Microsoft released in a given month, sorted by severity. Filter by product to scope it to your environment.