Is kernel.org Safe? Security Score 95.7/100 | CyStack
kernel.org
The Linux Kernel Archives
Industry
Computers, Electronics and Technology / Programming and Developer Software
Origin
United States
Global rank
#61,473
Rank in United States
#46,667
Updated at
A+95.7/100
Security level
Exceptional
Data confidence
High
Scope checked
100%
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.
Is the website “kernel.org” safe?
As of October 16, 2026 at 06:43, kernel.org has a security score of 95.7/100 (grade A+: “Exceptional”). CyStack’s automated assessment recorded 7 issues to review after completing 100% of applicable checks. The website owner should address “DMARC blocking policy” first, then review the remaining items in order of impact.
Does kernel.org show known scam, phishing, or malware signals?
At assessment time, CyStack did not find kernel.org 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.
Potentially exposed domain email addressesChecks infostealer data only for email addresses whose domain exactly matches this target. A record is not counted merely because someone visited or signed in to this website.5 matching email exposure records
5Matching email exposure records
1Related infected devices (estimated)
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
What affects the security of kernel.org?
A valid SSL certificate still does not prove that kernel.org 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.
Does kernel.org use HTTPS, and is its SSL certificate valid?
kernel.org used a valid SSL certificate at assessment time, valid until January 12, 2027. This status may change when the certificate expires or the server configuration changes.
Data compiled from CyStack cybersecurity monitoring systems
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.
These 3 failed checks or warnings have the greatest impact on the result for kernel.org.
DMARC blocking policyThe effective DMARC policy is quarantine and applies to 100% of messages.High
Why it matters
A policy of quarantine or reject tells receiving services to move suspicious mail to spam or refuse it. A monitoring-only policy (p=none) records the problem but does not ask receivers to stop spoofed mail.
What to do
After every legitimate sender passes DMARC, move gradually to quarantine and then reject, covering 100% of messages.
Potentially sensitive subdomainsCyStack confirmed at least 133 active DNS subdomains of kernel.org. 7 names may expose sensitive services; discovery was partial, so more may exist.Medium
Why it matters
Names containing admin, development, staging, VPN, database, or monitoring terms may point attackers toward valuable systems. A name alone does not prove exposure, but it identifies a surface that should be reviewed.
What to do
SPF protection levelThe terminal SPF policy is ~all.Medium
Why it matters
The final SPF rule tells receiving services how confidently they should reject unlisted senders. A permissive result allows more spoofed mail to appear legitimate than a hard fail (-all).
What to do
Confirm that every legitimate sender is included, then end the SPF record with -all.
Leak evidenceMost recent observation:
Email addressRelated infected deviceInfection evidenceRecorded time
Email addressC**************@kernel.orgRelated infected deviceNo safely shareable device details are available for this record.IOC reference: IOC-39256356D3Infection evidenceStealCRecorded timeEmail addressS******@kernel.orgRelated infected deviceNo safely shareable device details are available for this record.IOC reference: IOC-39256356D3Infection evidenceStealCEmail addressW***************@kernel.orgRelated infected deviceNo safely shareable device details are available for this record.IOC reference: IOC-39256356D3Infection evidenceStealCEmail addressE*******@kernel.orgRelated infected deviceNo safely shareable device details are available for this record.IOC reference: IOC-39256356D3Infection evidenceStealCEmail addressI*************@kernel.orgRelated infected deviceNo safely shareable device details are available for this record.IOC reference: IOC-39256356D3Infection evidenceStealC
Data provided by
Discovered subdomains (133+)Subdomains discovered by CyStack, with sensitive-looking names shown first. Availability is verified during this assessment; individual subdomains have not been separately security-tested.Partial
admin.wiki.kernel.orgSensitive-lookingAdmin system
Public web contextThe website title, description, industry and popularity.Website rankings and industry category are based on data from Similarweb
Page title
The Linux Kernel Archives
Website category
Computers, Electronics and Technology / Programming and Developer Software
Description
–
Global rank
#61,473
Rank in United States
#46,667
Rank in industry
#928
Final URL
https://kernel.org/
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.
Have @kernel.org email addresses appeared in exposed data or information-stealer (infostealer) logs?
There are currently 5 exposed email records matching the kernel.org domain. These records may be old or already resolved. The website owner should verify them before resetting passwords or locking related accounts.
Which public IPs, services, and ports does kernel.org expose?
The assessment observed 2 public IPs and 2 open ports for kernel.org. An open port is not the same as a vulnerability, but the website owner should keep every public service updated and appropriately restrict access.
How many subdomains of kernel.org have been discovered?
The assessment observed 133+ public subdomains of kernel.org. This list can reveal additional entry points such as APIs, administration systems, or test environments, but it does not mean that every subdomain is risky.
Industry
Updated at 
United States
