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Reachable AssertionWeakness · CWE-617

CVE-2026-3608

HIGH · 7.5 CVSS v3.1 Published 2026-03-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
Sending a maliciously crafted message to the kea-ctrl-agent, kea-dhcp-ddns, kea-dhcp4, or kea-dhcp6 daemons over any configured API socket or HA listener can cause the receiving daemon to exit with a stack overflow error. This issue affects Kea versions 2.6.0 through 2.6.4 and 3.0.0 through 3.0.2.

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

A stack-based buffer overflow vulnerability exists in multiple Kea DHCP server daemons (kea-ctrl-agent, kea-dhcp-ddns, kea-dhcp4, kea-dhcp6). An attacker can send a maliciously crafted message over a configured API socket or HA listener to trigger a stack overflow, causing the affected daemon to crash and exit.

MitigationUpgrade Kea to version 2.6.5 or later, or 3.0.3 or later. Consider restricting access to API sockets and HA listeners using network segmentation or authentication while the upgrade is being planned.

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
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/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 checks

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

  1. Identify installed Kea DHCP components
    Run 'dpkg -l | grep kea' or 'rpm -qa | grep kea' to list installed Kea packages. Check for: kea-ctrl-agent, kea-dhcp-ddns, kea-dhcp4, kea-dhcp6
    Affected if Any of these Kea components are installed and version is 2.6.4 or lower, or 3.0.2 or lower
  2. Determine Kea version
    Run 'kea-dhcp4 --version' (or the appropriate binary name for the installed component). Compare the version number to the affected ranges: versions 2.x at or below 2.6.4, and versions 3.x at or below 3.0.2
    Affected if Installed version falls at or below 2.6.4 for 2.x releases, or at or below 3.0.2 for 3.x releases
  3. Check if command-channel/API socket is enabled
    Inspect Kea config files (typically in /etc/kea/) for 'command-channel' or 'control-channel' sections. Look for Unix socket or TCP socket definitions in the configuration. Example: check /etc/kea/kea-dhcp4.conf for 'socket-name' or 'socket-type' entries under Dhcp4 > control-socket
    Affected if Command-channel is configured and listening on a socket accessible to untrusted network paths or users
  4. Check if HA (High Availability) is enabled
    Inspect Kea config files for 'high-availability' or 'ha' sections. Look for 'listeners' or 'peers' configurations under Dhcp4 > high-availability or similar paths in /etc/kea/kea-dhcp4.conf, kea-dhcp6.conf, or kea-ctrl-agent.conf
    Affected if High Availability is enabled with listener connections that could accept remote messages
  5. Verify network exposure of API sockets
    Review socket binding configuration. Check if command-channel TCP sockets bind to 0.0.0.0 or are otherwise exposed beyond localhost. For Unix sockets, verify file permissions using 'ls -la /var/run/kea/' or similar path
    Affected if API sockets are bound to non-localhost addresses or Unix socket files have overly permissive access (world-readable/writable)

A user is affected if a Kea DHCP component (kea-ctrl-agent, kea-dhcp-ddns, kea-dhcp4, or kea-dhcp6) is installed at version 2.6.4 or lower (or 3.0.2 or lower) AND the command-channel or HA listener is enabled and accessible to untrusted actors.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Kea to version 2.6.5 or later, or 3.0.3 or later. Consider restricting access to API sockets and HA listeners using network segmentation or authentication while the upgrade is being planned.

Recommended fix High confidence

Kea 3.0.3 or later (or Kea 2.6.5 if staying on the 2.x branch)

  1. 1. Identify the currently installed Kea version by running 'kea-dhcp4 --version' or checking the package manager
  2. 2. Download the fixed Kea release from the official ISC download site (downloads.isc.org) or use your system's package manager
  3. 3. For RHEL/CentOS systems: run 'yum update kea' or 'dnf update kea'
  4. 4. For Debian/Ubuntu systems: run 'apt-get update && apt-get install kea'
  5. 5. Restart the affected services in the correct order: 'systemctl restart kea-dhcp-ddns' then 'systemctl restart kea-dhcp4' and/or 'systemctl restart kea-dhcp6'
  6. 6. Verify the services are running: 'systemctl status kea-dhcp4 kea-dhcp6 kea-dhcp-ddns kea-ctrl-agent'
Caveat Review ISC release notes for any configuration or feature changes between your current version and the upgrade target

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

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2026-3608 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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