Vistra Corp · Domain Security

Vistra Energy Domain Security

Domain security

Domain security posture for Vistra Corp, probed live across 10 host(s) and 7 registrable domain(s). 10 host(s) serve HTTPS (up to TLSv1.3); 7 advertise HSTS. Email/DNS controls: DNSSEC absent, SPF present, DMARC present (p=none).

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Transport & Host Security

www.vistracorp.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: no · cert expires: Oct 21 17:18:14 2026 GMT
hub.vistracorp.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Oct 21 17:18:14 2026 GMT
investor.vistracorp.com
HTTPS: yes · TLS: TLSv1.2 · HSTS: yes · cert expires: Oct 3 06:43:41 2026 GMT
www.txu.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: no · cert expires: Oct 24 14:59:50 2026 GMT
services.txu.com
HTTPS: yes · TLS: TLSv1.2 · HSTS: yes · cert expires: Oct 24 14:59:50 2026 GMT
www.dynegy.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Nov 13 23:59:59 2026 GMT
www.ambitenergy.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Sep 8 23:08:27 2026 GMT
www.homefieldenergy.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Nov 10 23:59:59 2026 GMT
www.trieagleenergy.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: no · cert expires: Oct 21 23:09:01 2026 GMT
www.energyharbor.com
HTTPS: yes · TLS: TLSv1.3 · HSTS: yes · cert expires: Sep 12 13:29:31 2026 GMT

Domain (DNS/Email) Security

vistracorp.com
DNSSEC: no · SPF: yes · DMARC: yes (p=none) · CAA: none
txu.com
DNSSEC: no · SPF: yes · DMARC: yes (p=none) · CAA: none
dynegy.com
DNSSEC: no · SPF: yes · DMARC: yes (p=none) · CAA: none
ambitenergy.com
DNSSEC: no · SPF: yes · DMARC: yes (p=none) · CAA: none
homefieldenergy.com
DNSSEC: no · SPF: yes · DMARC: no · CAA: none
trieagleenergy.com
DNSSEC: no · SPF: yes · DMARC: no · CAA: none
energyharbor.com
DNSSEC: no · SPF: yes · DMARC: yes (p=none) · CAA: none

Source

Domain Security

vistra-energy-domain-security.yml Raw ↑ 
generated: '2026-07-27'
method: probed
source: live DNS/TLS/HTTP probes of every Vistra Corp controlled host in apis.yml
note: >-
  Vistra Corp publishes no API host, so every host probed here is a corporate,
  retail-brand, investor or customer-portal web property. There are no API
  servers to probe. Absence of a record (no CAA anywhere, no HSTS on
  www.vistracorp.com or www.txu.com) is observed data, not a gap in the probe.
hosts:
- host: www.vistracorp.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Oct 21 17:18:14 2026 GMT
  hsts: null
- host: hub.vistracorp.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Oct 21 17:18:14 2026 GMT
  hsts: true
  hsts_max_age: 63072000
- host: investor.vistracorp.com
  https: true
  tls_version: TLSv1.2
  cert_expires: Oct  3 06:43:41 2026 GMT
  hsts: true
  hsts_max_age: 31536000
- host: www.txu.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Oct 24 14:59:50 2026 GMT
  hsts: null
- host: services.txu.com
  https: true
  tls_version: TLSv1.2
  cert_expires: Oct 24 14:59:50 2026 GMT
  hsts: true
  hsts_max_age: 31536000
- host: www.dynegy.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Nov 13 23:59:59 2026 GMT
  hsts: true
  hsts_max_age: 63072000
- host: www.ambitenergy.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Sep  8 23:08:27 2026 GMT
  hsts: true
  hsts_max_age: 31536000
- host: www.homefieldenergy.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Nov 10 23:59:59 2026 GMT
  hsts: true
  hsts_max_age: 63072000
- host: www.trieagleenergy.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Oct 21 23:09:01 2026 GMT
  hsts: false
- host: www.energyharbor.com
  https: true
  tls_version: TLSv1.3
  cert_expires: Sep 12 13:29:31 2026 GMT
  hsts: true
  hsts_max_age: 63072000
domains:
- domain: vistracorp.com
  dnssec: false
  caa: []
  spf: true
  dmarc: true
  dmarc_policy: none
- domain: txu.com
  dnssec: false
  caa: []
  spf: true
  dmarc: true
  dmarc_policy: none
- domain: dynegy.com
  dnssec: false
  caa: []
  spf: true
  dmarc: true
  dmarc_policy: none
- domain: ambitenergy.com
  dnssec: false
  caa: []
  spf: true
  dmarc: true
  dmarc_policy: none
- domain: homefieldenergy.com
  dnssec: false
  caa: []
  spf: true
  dmarc: false
- domain: trieagleenergy.com
  dnssec: false
  caa: []
  spf: true
  dmarc: false
- domain: energyharbor.com
  dnssec: false
  caa: []
  spf: true
  dmarc: true
  dmarc_policy: none
summary:
  hosts_probed: 10
  https_all: true
  tls13_hosts: 8
  tls12_hosts: 2
  hsts_hosts: 7
  hsts_absent_hosts:
  - www.vistracorp.com
  - www.txu.com
  - www.trieagleenergy.com
  domains_probed: 7
  dnssec_domains: 0
  caa_domains: 0
  spf_domains: 7
  dmarc_domains: 5
  dmarc_enforcing_domains: 0
  observation: >-
    Every Vistra domain publishes SPF, none publishes CAA or enables DNSSEC, and
    every DMARC record found is p=none (monitor only, no enforcement). The two
    highest-traffic customer-facing hosts, www.vistracorp.com and www.txu.com,
    return no Strict-Transport-Security header.