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RecursorApplication · Powerdns

CVE-2025-59023

HIGH · 8.2 CVSS v3.1 Published 2026-02-09
Fix available
A fix is available. Upgrade to 5.1.8 / 5.2.6 or later.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
Crafted delegations or IP fragments can poison cached delegations in Recursor.

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 · high confidence

This is a cache poisoning vulnerability in PowerDNS Recursor where specially crafted DNS delegations or malformed IP fragments can corrupt the resolver's cached delegation information. An attacker could exploit this to redirect DNS queries for legitimate domains to malicious name servers, enabling further attacks like phishing or man-in-the-middle operations.

MitigationUpgrade PowerDNS Recursor to the patched version addressing CVE-2025-59023. If immediate patching is not possible, consider implementing additional validation on DNS responses at network perimeter or deploying DNS security extensions (DNSSEC) where applicable.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
RecursorApplication
Affected:>= 5.1.0, < 5.1.8>= 5.2.0, < 5.2.6>= 5.3.0, < 5.3.1

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
High
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify PowerDNS Recursor version
    Run 'pdns_recursor --version' or check the installed package version via package manager (e.g., 'rpm -q pdns-recursor' or 'dpkg -l pdns-recursor')
    Affected if Installed version is 5.1.0 through 5.1.7, 5.2.0 through 5.2.5, or 5.3.0
  2. Verify the Recursor service is active
    Run 'systemctl status pdns-recursor' or check process status via 'ps aux | grep pdns_recursor'
    Affected if Service is running and version is in the affected ranges listed above
  3. Confirm recursion is enabled
    Inspect the Recursor configuration file (commonly /etc/pdns-recursor/recursor.conf) for 'allow-recursion=yes' or 'recursor=yes' settings, or run 'pdns_recursor --config | grep -i recurs'
    Affected if Recursion is enabled and the installed version falls within the vulnerable ranges

You are affected if PowerDNS Recursor is running with a version in 5.1.0-5.1.7, 5.2.0-5.2.5, or 5.3.0 and recursion is enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Upgrade available Upgrade to 5.1.8 / 5.2.6 / 5.3.1 or later
Fixed in 5.1.85.2.65.3.1
Interim mitigation

Upgrade PowerDNS Recursor to the patched version addressing CVE-2025-59023. If immediate patching is not possible, consider implementing additional validation on DNS responses at network perimeter or deploying DNS security extensions (DNSSEC) where applicable.

Recommended fix High confidence

5.3.1 or later (latest stable 5.x release)

  1. 1. Identify the currently installed PowerDNS Recursor version using 'rec_control version' or checking the package version
  2. 2. Based on your current version, plan the upgrade path: for 5.1.x upgrade to 5.1.8+, for 5.2.x upgrade to 5.2.6+, for 5.3.x upgrade to 5.3.1+
  3. 3. Back up the Recursor configuration files (typically recursor.conf) and the existing recursor database if using one
  4. 4. Update your package repository to ensure you can fetch the latest packages
  5. 5. Install the new package via your package manager (e.g., apt-get install pdns-recursor, yum install pdns-recursor)
  6. 6. Verify the new version is running with 'rec_control version'
  7. 7. Review recursor.conf for any deprecated settings that may need adjustment
  8. 8. Monitor logs for any errors after upgrade
Caveat Review release notes for any configuration or behavior changes between your current and target version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Recursor Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-59023 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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