generated: '2026-08-11' method: probed source: live DNS/TLS/HTTP probes of apis.yml + OpenAPI hosts note: >- Baseline written by 0-working/probe-domain-security.py (sybilion.dev tree only), then extended by hand with the sybilion.com corporate/marketing domain, the auth0.sybilion.com identity host, and observed HSTS headers — none of which are reachable from apis.yml as it stood. Headline: TLS 1.3 everywhere and HSTS on the two Cloudflare-fronted web properties, but the API and MCP hosts return NO HSTS header at all, and neither registrable domain has DNSSEC, CAA, or SPF. sybilion.dev — the domain that serves the API, the MCP server and the developer portal — has no DMARC record either. hosts: - host: sybilion.dev role: developer portal (SPA) https: true tls_version: TLSv1.3 cert_expires: Nov 4 11:00:55 2026 GMT hsts: false - host: api.sybilion.dev role: REST API https: true tls_version: TLSv1.3 cert_expires: Nov 4 11:00:55 2026 GMT hsts: false hsts_observed: 'no strict-transport-security header on 401 /api/v1/me or 405 /health, 2026-08-11' - host: mcp.sybilion.dev role: hosted MCP server https: true tls_version: TLSv1.3 cert_expires: Nov 4 11:00:55 2026 GMT hsts: false hsts_observed: 'no strict-transport-security header on the 401 tools/list challenge, 2026-08-11' - host: www.sybilion.com role: corporate / marketing site (Webflow behind Cloudflare) https: true tls_version: TLSv1.3 cert_expires: Oct 8 13:09:26 2026 GMT hsts: true hsts_max_age: 31536000 hsts_include_subdomains: false note: 'https://sybilion.com/ redirects to https://www.sybilion.com/ (200)' - host: auth0.sybilion.com role: Auth0 custom domain — portal login and MCP OAuth issuer https: true hsts: true hsts_max_age: 31536000 hsts_include_subdomains: true domains: - domain: sybilion.dev role: product domain (API, MCP, docs, portal) dnssec: false ds_record: false caa: [] spf: false dmarc: false dmarc_policy: null txt_records_present: [google-site-verification] - domain: sybilion.com role: corporate domain (website, email, Auth0 custom domain) dnssec: false ds_record: false caa: [] spf: false dmarc: true dmarc_policy: quarantine dmarc_record: 'v=DMARC1; p=quarantine; rua=mailto:@dmarc-reports.cloudflare.net;' txt_records_present: [MS=, google-site-verification x2, anthropic-domain-verification, kok6w5nrvl] note: >- DMARC is at p=quarantine with Cloudflare aggregate reporting, but there is NO v=spf1 record on the apex, so DMARC can only pass via DKIM alignment. support@sybilion.com is the published support and security-report address, which makes the missing SPF record worth flagging. findings: - { severity: low, item: 'no CAA records on either domain — any CA may issue' } - { severity: low, item: 'no DNSSEC on either domain' } - { severity: medium, item: 'no HSTS on api.sybilion.dev or mcp.sybilion.dev, the two credential-bearing hosts' } - { severity: medium, item: 'no SPF on sybilion.com despite DMARC p=quarantine' } - { severity: medium, item: 'no DMARC at all on sybilion.dev' } - { severity: info, item: 'TLS 1.3 on every host; certificates valid through Oct/Nov 2026' }