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Updated at The higher the score, the more externally observable protections the system has recorded. This page does not certify that the website is reputable, legitimate, or completely free of vulnerabilities.
As of September 17, 2026 at 15:55, jsdelivr.net has a security score of 81.8/100 (grade U: “Unrated”), but this result is provisional because some required evidence is incomplete. CyStack’s automated assessment recorded 6 issues to review after completing 50.2% of applicable checks. The website owner should address “Email spoofing protection (DMARC)” first, then review the remaining items in order of impact.
At assessment time, CyStack did not find jsdelivr.net or related infrastructure on any scam, phishing, or malware warning list after checking 5 online reputation sources. This result reflects external observations; it does not guarantee absolute safety or verify the organization’s legal status or reputation.
These matching email records were observed previously, but they may already have been addressed or may no longer be valid. The device count estimates infected devices associated with these email records; it is not the number of devices owned by the organization.
Frequently asked questions
A valid SSL certificate still does not prove that jsdelivr.net is safe, legitimate, or free of scam signals. For a more complete assessment, this report also checks phishing and malware, exposed email records, IPs and open ports, subdomains, technologies, and CVEs that may apply to observed versions.
HTTPS on jsdelivr.net could not be reached during this assessment, so its SSL certificate and transport encryption could not be evaluated.
Review HTTPS and certificateData sources
CyStack compiles scan results from its internal cybersecurity monitoring systems, including CyStack VulnScan and CyStack Threat Intelligence, together with publicly available Internet data. The assessment only observes and analyzes information already available; it does not attempt unauthorized access, test passwords, send exploit code, or change or disrupt the assessed system.
CyStack VulnScan continuously discovers assets, validates vulnerabilities, and helps security teams prioritize remediation across the enterprise.
These 3 failed checks or warnings have the greatest impact on the result for jsdelivr.net.
Why it matters
DMARC lets the domain owner tell receiving services what to do when the visible From address is not verified by SPF or DKIM. Without DMARC, attackers have more opportunity to impersonate the domain in phishing email.
What to do
Publish a DMARC record at _dmarc, begin by collecting reports, and confirm that legitimate senders pass before applying a blocking policy.
Evidence and check scope
References
Data provided by
This is a quick, point-in-time check from outside the organization. It can surface visible risks, but it does not replace penetration testing or an authenticated assessment.
Evidence and check scope
References
Review the masked evidence and observation time, validate affected accounts and devices, then reset active credentials and sessions, enforce MFA, and remove malware where confirmed.
Evidence and check scope
8 additional evidence fields are not shown here.
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