CVE-2026-33612
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 · uneditedA malicious authoritative server can send a crafted zone via the ZoneToCache function that leads to cache poisoning.
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 vulnerability in the ZoneToCache function of affected DNS software allows a malicious authoritative nameserver to inject crafted DNS zones that poison the cache. This enables an attacker to redirect legitimate DNS queries to attacker-controlled infrastructure.
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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:L
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 DNS software and versionRun command to determine DNS server software and its version (for example: 'named -v' for BIND, 'dnsdist --version', or check package manager)Affected if The installed version falls within the affected range for the specific DNS software in use
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Confirm caching resolver roleExamine DNS server configuration to verify if the server functions as a caching resolver (look for recursion-enabled, forwarder, or resolver settings in named.conf or equivalent config file)Affected if The server is configured as a caching resolver that accepts and caches zones from upstream authoritative servers; pure authoritative-only servers are not affected by this cache poisoning flaw
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Check DNSSEC validation statusInspect DNS server configuration for DNSSEC validation settings (for example: check for 'dnssec-validation auto' or 'validate-answers' in configuration)Affected if DNSSEC validation is disabled or not enforced, allowing unsigned or fraudulently signed zone data to be accepted into the cache
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Review upstream authoritative server trustExamine configuration for trusted zone transfers or zone imports from external authoritative servers, particularly any 'zone' statements pointing to external authoritiesAffected if The server is configured to accept zones from untrusted or insufficiently vetted upstream authoritative nameservers
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Inspect cache for unexpected recordsQuery the DNS cache directly or dump cache contents to inspect for suspicious or unexpected resource records, particularly those with unusually long TTLsAffected if The cache contains DNS records that were not intentionally provisioned or that resolve to unexpected infrastructure
A system is affected if it runs vulnerable DNS software as a caching resolver with DNSSEC validation disabled or not enforced, allowing potential cache poisoning from malicious authoritative nameservers.
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 dataEnable and require DNSSEC validation on the DNS resolver to cryptographically verify the authenticity of DNS records. Additionally, limit trust in upstream authoritative servers and monitor for unexpected cache modifications.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33612 — 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-2026-33612 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
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