CVE-2026-36478
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn issue in Technitium DNS Server v.14.3 and before allows a remote attacker to cause a denial of service via the DnsServerApp.exe, DnsServerApp.dll, TechnitiumLibrary.Net/Dns/DnsClient.cs components
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA denial of service vulnerability exists in Technitium DNS Server v14.3 and earlier versions. The issue affects multiple components including DnsServerApp.exe, DnsServerApp.dll, and TechnitiumLibrary.Net/Dns/DnsClient.cs. A remote attacker can exploit this vulnerability to cause the DNS server to become unavailable, disrupting name resolution services.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Technitium DNS Server versionCheck the installed version through the DNS Server web interface (typically http://localhost:5380), or inspect the DnsServerApp.exe file properties for version information, or run 'dnscmd' or check the program's About section in the management console.Affected if The installed version is 14.3 or any version number lower than 14.3.
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Verify vulnerable components existLocate DnsServerApp.exe, DnsServerApp.dll, and TechnitiumLibrary.Net/Dns/DnsClient.cs in the installation directory (commonly found in C:\Program Files\Technitium\DNS Server or /opt/technitium/dns). Check file version properties or use 'dir' or 'ls' to list these files.Affected if These files are present in versions 14.3 or earlier.
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Confirm DNS server service is activeCheck if the Technitium DNS Server service is running by using Service Manager on Windows (services.msc) or running 'systemctl status technitium-dns' or 'sc query DNSServer' on Linux/Windows.Affected if The DNS server is actively running and processing requests, making it vulnerable to the DoS condition.
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Review DNS server configuration for exposureInspect the DNS server configuration file (typically config.json in the installation directory) to confirm DNS services are bound to network interfaces accessible from untrusted networks, or check the web management console DNS settings.Affected if The DNS server is configured to accept queries from network clients (not limited to localhost only).
A user is affected if they are running Technitium DNS Server version 14.3 or earlier with the DNS service active and accessible to network clients.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade Technitium DNS Server to a version beyond v14.3 once the patch is available. Implement network segmentation and rate limiting on DNS services as a temporary defensive measure until the update can be applied.
- Consultation3.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-36478 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-36478 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data