CVE-2025-55086
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 · uneditedIn NetXDuo version before 6.4.4, a networking support module for Eclipse Foundation ThreadX, in the DHCPV6 client there was an unchecked index extracting the server DUID from the server reply. With a crafted packet, an attacker could cause an out of memory read.
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 confidenceOut-of-bounds read vulnerability in the NetX Duo DHCPV6 client where an unchecked index is used when extracting the server DUID from a server reply. A remote attacker can send a crafted DHCPV6 packet to cause an out-of-memory read.
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< 6.4.4.202503CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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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Identify NetX Duo library versionLocate the NetX Duo version definition in your build - typically found in nx_port.h, nx_api.h, or the build configuration file. Search for version constants like NX_VERSION_MAJOR, NX_VERSION_MINOR, or version strings containing 'NetX Duo'. Compare the version to 6.4.4.202503.Affected if The installed version is less than 6.4.4.202503
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Verify DHCPV6 client is enabledCheck your NetX Duo configuration header (usually nx_user.h or a custom configuration file) for the define NX_DHCPV6_CLIENT. Look for lines like '#define NX_DHCPV6_CLIENT' or '#define NX_DHCPV6_ENABLE'. If commented out, the DHCPV6 client is not compiled in.Affected if NX_DHCPV6_CLIENT is defined/enabled in the build configuration
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Confirm DHCPV6 client is instantiated and runningSearch your application source code for calls to nx_dhcpv6_create() to determine if the DHCPV6 client is actually being created and started in the firmware. Review the main initialization routine.Affected if The code calls nx_dhcpv6_create() and the DHCPV6 client is actively running
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Check for DHCPV6 network exposureReview your network configuration and firewall rules to determine if the device is directly reachable on UDP ports 546/547 (DHCPV6 client/server ports) from untrusted networks. Inspect network interface bindings.Affected if The device can receive DHCPV6 packets from external or untrusted network sources
You are affected if your NetX Duo version is below 6.4.4.202503 AND the DHCPV6 client is enabled and actively running in your deployment.
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.
dbcve · scoped6.4.4.202503
Upgrade NetX Duo to version 6.4.4 or later. As interim measures, restrict network access to DHCPV6 servers and filter unexpected DHCPV6 traffic at network boundaries.
NetX Duo 6.4.4.202503 or later
- 1. Identify all deployments of ThreadX NetX Duo in your environment
- 2. Check the current NetX Duo version in use (likely via firmware version or library version)
- 3. If the version is below 6.4.4.202503, plan for an upgrade
- 4. Obtain NetX Duo version 6.4.4.202503 or later from the official Eclipse Foundation ThreadX distribution
- 5. Replace the vulnerable NetX Duo library with the updated version
- 6. Rebuild and redeploy affected firmware/images
- 7. Verify the upgrade was successful by checking the new version number
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-55086 — 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-2025-55086 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
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