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DnsdistApplication · Powerdns

CVE-2026-24028

HIGH · 8.2 CVSS v3.1 Published 2026-03-31
Fix available
A fix is available. Upgrade to 1.9.12 / 2.0.3 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
An attacker might be able to trigger an out-of-bounds read by sending a crafted DNS response packet, when custom Lua code uses newDNSPacketOverlay to parse DNS packets. The out-of-bounds read might trigger a crash, leading to a denial of service, or access unrelated memory, leading to potential information disclosure.

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

An out-of-bounds read vulnerability exists in the newDNSPacketOverlay function used by custom Lua code to parse DNS response packets. Attackers can send specially crafted DNS packets that cause the parser to read beyond allocated buffer boundaries, potentially causing a denial of service through crashes or information disclosure by accessing adjacent memory.

MitigationReview and fix bounds checking in the newDNSPacketOverlay function to validate packet sizes before reading DNS packet data. Consider input validation on DNS response packets before passing them to Lua parsing functions.

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, < 1.9.12>= 2.0.0, < 2.0.3

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
Low
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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. Check installed dnsdist version
    Run 'dnsdist --version' or check the package manager for the installed version
    Affected if The version is >= 1.9.0 and < 1.9.12, or >= 2.0.0 and < 2.0.3
  2. Locate custom Lua configuration files
    Look for .lua files in /etc/dnsdist/ and other configuration directories, or check the dnsdist configuration for 'loadLuaScript' directives
    Affected if Custom Lua scripts are loaded via loadLuaScript or similar directives
  3. Search for newDNSPacketOverlay usage in Lua code
    Grep your Lua configuration files for 'newDNSPacketOverlay' function calls
    Affected if Your Lua code calls the newDNSPacketOverlay function to process DNS packets
  4. Verify dnsdist accepts external DNS responses
    Check the dnsdist configuration for downstream servers or frontend listeners that process DNS responses from network sources
    Affected if Dnsdist is configured to receive and process DNS responses from network sources (not only locally generated)
  5. Identify Lua code paths handling DNS responses
    Review any Lua code that processes DNS response packets via newDNSPacketOverlay to confirm it handles packets from untrusted sources
    Affected if The newDNSPacketOverlay function is used to parse DNS responses that originate from external or untrusted sources

You are affected if you run a vulnerable dnsdist version AND have custom Lua code using newDNSPacketOverlay to process DNS responses from network sources.

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 1.9.12 / 2.0.3 or later
Fixed in 1.9.122.0.3
Interim mitigation

Review and fix bounds checking in the newDNSPacketOverlay function to validate packet sizes before reading DNS packet data. Consider input validation on DNS response packets before passing them to Lua parsing functions.

Recommended fix High confidence

Upgrade to dnsdist 1.9.12 (for 1.9.x branch) or 2.0.3 (for 2.0.x branch)

  1. 1. Identify the currently running dnsdist version using 'dnsdist --version' or checking the package version.
  2. 2. If running dnsdist >= 1.9.0 and < 1.9.12, plan upgrade to version 1.9.12.
  3. 3. If running dnsdist >= 2.0.0 and < 2.0.3, plan upgrade to version 2.0.3.
  4. 4. Review the dnsdist 1.9.12 and 2.0.3 release notes for any relevant changes before upgrading.
  5. 5. Before upgrading, test the new version in a staging environment to ensure compatibility with existing configurations and Lua scripts.
  6. 6. After upgrade, verify that custom Lua code using newDNSPacketOverlay functions correctly.

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

Fix this in Dnsdist Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.

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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-2026-24028 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