Palo Alto ACE/PCNSE
Cisco CCNA/CCNP/CCIE Security
Cisco CCNA/CCNP/CCIE RnS
Checkpoint CCSA/CCSE
Juniper SRX
Cisco Meraki and Aruba APs
VmWare
CompTIA Linux+/LPIC1
CompTIA Network+/Security+
ITIL
Microsoft MCSA
Security Advisories:
US-CERT: https://www.us-cert.gov/ncas/current-activity
Palo Alto: https://securityadvisories.paloaltonetworks.com
Checkpoint: https://www.checkpoint.com/advisories/
https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsecurityalerts=#severity=&type=Security+Alerts&product=&version=
Cisco: https://tools.cisco.com/security/center/publicationListing.x
Meraki: https://meraki.cisco.com/blog/cisco-meraki-customer-advisories/
Juniper: https://kb.juniper.net/InfoCenter/index?page=content&channel=SECURITY_ADVISORIES
EoL links:
Cisco:
https://www.cisco.com/c/en/us/products/security/asa-5500-series-next-generation-firewalls/eos-eol-notice-listing.html
https://www.curvature.com/resources/cisco-end-of-life-guide
Palo Alto:
https://www.paloaltonetworks.com/services/support/end-of-life-announcements/end-of-life-summary
Meraki:
https://documentation.meraki.com/zGeneral_Administration/Other_Topics/Product_End-of-Life_(EOL)_Policies
Checkpoint:
https://www.checkpoint.com/support-services/support-life-cycle-policy/
CVE (Common Vulnerabilities and Exposures) and CVSS (Common Vulnerability Scoring System):
https://www.cvedetails.com/cvss-score-distribution.php
https://nvd.nist.gov/vuln-metrics/cvss
https://cve.mitre.org/
Important Organizations:
United States Computer Emergency Readiness Team (US-CERT)
National Cybersecurity and Communications Integration Center (NCCIC)
Cybersecurity and Infrastructure Security Agency (CISA)
National Institute of Standards and Technology (NIST)
National Cyber Security Centre (NCSC)
Government Communications Headquarters (GCHQ)
(CREST)