CVE-2026-52690
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 · uneditedSpoofing replies to Recursor might mark an IP of an authoritative server as not supporting EDNS, causing valdiation of DNSSEC records served by that server to fail.
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 spoofing vulnerability in DNS Recursor allows attackers to send伪造 replies that incorrectly mark authoritative DNS servers as not supporting EDNS, causing DNSSEC validation of records from those servers to fail.
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
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:H/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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Confirm you run a DNS RecursorIdentify any DNS recursive resolver software in your environment (such as BIND, Unbound, PowerDNS Recursor, Knot Resolver, or others). Check running processes, installed packages, or configuration files that indicate DNS recursive resolution services.Affected if A DNS recursive resolver is deployed in your environment and handles DNSSEC validation.
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Verify DNSSEC validation is enabledCheck the DNS recursor configuration for DNSSEC validation settings. Common configuration directives include 'dnssec-validate', 'dnssec', 'enable-dnssec', or 'dnssec-mode'. Ensure the feature is set to 'yes', 'true', 'validate', or similar enabled state.Affected if DNSSEC validation is enabled, as the vulnerability causes DNSSEC validation failures for affected authoritative servers.
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Check the recursor version against the affected rangeQuery the DNS recursor software version (often via 'version' command in dig, command-line flags like '-v', or package metadata). Compare your installed version to any vendor-provided affected version ranges for this vulnerability.Affected if The installed DNS recursor version falls within the vulnerable version range.
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Inspect logs for DNSSEC validation failuresReview DNS recursor logs for validation failures, trusted anchor issues, or security-level errors. Look for messages indicating that DNSSEC validation is failing for specific domains or authoritative servers, especially after recent periods.Affected if Logs show unusual or elevated DNSSEC validation failures for records from certain authoritative servers.
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Check for non-EDNS capable server markingsExamine recursor cache, statistics, or debugging output that tracks authoritative server capabilities. Look for indicators that servers are being marked as not supporting EDNS when they should, or for records of EDNS capability changes.Affected if The recursor shows authoritative servers incorrectly marked as non-EDNS capable, leading to validation issues.
If DNSSEC validation is enabled and your DNS recursor version is within the affected range, your environment is vulnerable to spoofed replies that can cause DNSSEC validation failures.
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 dataImplement validation of EDNS responses to detect spoofed replies, or add mechanisms to verify authoritative server EDNS capabilities through multiple independent sources before marking servers as non-EDNS capable.
- Consultation3.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-52690 — 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-2026-52690 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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- 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