dbcve.org
DnsdistApplication · Powerdns

CVE-2026-33598

CRITICAL · 9.1 CVSS v3.1 Published 2026-04-22
Fix available
A fix is available. Upgrade to 1.9.13 / 2.0.4 or later.
See remediation →
100/100
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
A cached crafted response can cause an out-of-bounds read if custom Lua code calls getDomainListByAddress() or getAddressListByDomain() on a packet cache.

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 confidence

This is a memory safety vulnerability in PowerDNS (or similar DNS product) where custom Lua scripting can call getDomainListByAddress() or getAddressListByDomain() functions on the packet cache. When a crafted malicious response is cached, these Lua functions trigger an out-of-bounds read beyond allocated buffer boundaries, potentially exposing sensitive heap memory contents to an attacker.

MitigationDisable or restrict custom Lua code that interacts with the packet cache functions (getDomainListByAddress/getAddressListByDomain) until an official patch is available; network-side filtering may help block malicious crafted DNS responses from being cached.

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
DnsdistApplication
Affected:>= 1.9.0, < 1.9.13>= 2.0.0, < 2.0.4

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
High
Integrity
None
Availability
High

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

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

  1. Identify dnsdist version
    Run 'dnsdist --version' or check package manager (dpkg -r, rpm -qi) to get the installed version number
    Affected if The installed version falls within >= 1.9.0 and < 1.9.13, or >= 2.0.0 and < 2.0.4
  2. Verify Lua scripting is enabled
    Check configuration files (typically /etc/dnsdist/dnsdist.conf or similar) for 'setLua()' or 'LuaNonUDPRule()' functions, or inspect running process for Lua hooks
    Affected if Custom Lua code is loaded and active in the dnsdist configuration
  3. Confirm vulnerable functions are in use
    Search Lua configuration for calls to getDomainListByAddress() or getAddressListByDomain() functions interacting with the packet cache
    Affected if Either getDomainListByAddress() or getAddressListByDomain() is called in the Lua script on packet cache data
  4. Verify packet cache is active
    Check dnsdist configuration for packet cache settings (newCache(), 'setPacketCache()' or similar cache declarations) and runtime stats via dnsdist control socket using 'getPacketCache()'
    Affected if Packet caching is enabled and the vulnerable Lua functions are querying cached entries

A user is affected if dnsdist version is 1.9.0-1.9.12 or 2.0.0-2.0.3 AND custom Lua scripting that calls getDomainListByAddress/getAddressListByDomain on the packet cache is actively used.

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 1.9.13 / 2.0.4 or later
Fixed in 1.9.132.0.4
Interim mitigation

Disable or restrict custom Lua code that interacts with the packet cache functions (getDomainListByAddress/getAddressListByDomain) until an official patch is available; network-side filtering may help block malicious crafted DNS responses from being cached.

Recommended fix High confidence

dnsdist 1.9.13 (for 1.x branch) or dnsdist 2.0.4 (for 2.x branch)

  1. 1. Identify the current dnsdist version running in your environment using 'dnsdist --version' or checking your package manager
  2. 2. If running dnsdist 1.9.x (>=1.9.0, <1.9.13): Upgrade to dnsdist version 1.9.13 or later
  3. 3. If running dnsdist 2.0.x (>=2.0.0, <2.0.4): Upgrade to dnsdist version 2.0.4 or later
  4. 4. If running an older version (<1.9.0): Plan migration to 1.9.13+ or 2.0.4+ following the upgrade path
  5. 5. After upgrade, verify the new version is running: 'dnsdist --version'
  6. 6. Test that DNS load balancing and any custom Lua scripts using getDomainListByAddress() or getAddressListByDomain() function correctly
Caveat Minor version upgrades within same major version (1.x or 2.x) are typically low-risk; however, review release notes for any configuration or Lua API changes before upgrading

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

Fix this in Dnsdist Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
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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-2026-33598 in production — separate from our analysis above.

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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