CVE-2023-25526
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 · uneditedNVIDIA Cumulus Linux contains a vulnerability in neighmgrd and nlmanager where an attacker on an adjacent network may cause an uncaught exception by injecting a crafted packet. A successful exploit may lead to denial of service.
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 confidenceNVIDIA Cumulus Linux neighmgrd and nlmanager daemons fail to properly handle a specially crafted packet injected from an adjacent network, causing an uncaught exception that crashes the service and results in denial of service.
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< 5.5.0CVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/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 checksWork through these to decide whether this CVE applies to you.
-
Check Cumulus Linux versionRun 'cat /etc/cumulus/linux-version' or 'cumulus@switch:~$ cat /etc/os-release' to determine the installed versionAffected if The installed version is lower than 5.5.0
-
Verify neighmgrd daemon is runningRun 'systemctl status neighmgrd' or check if the process is active using 'ps aux | grep neighmgrd'Affected if The neighmgrd daemon is active and the Cumulus version is below 5.5.0
-
Verify nlmanager daemon is runningRun 'systemctl status nlmanager' or check if the process is active using 'ps aux | grep nlmanager'Affected if The nlmanager daemon is active and the Cumulus version is below 5.5.0
-
Check layer-2 network adjacency exposureInspect switch configuration for untrusted layer-2 neighbors; review MAC address table and neighbor entries with 'bridge fdb show' and 'ip neigh show'Affected if The switch has untrusted or unmanaged layer-2 adjacencies and runs an affected version
The environment is affected if running Cumulus Linux version below 5.5.0 with neighmgrd or nlmanager daemons active and exposed to untrusted adjacent network segments.
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 · scoped5.5.0
Apply the NVIDIA-provided patch or upgrade Cumulus Linux to a version that addresses this vulnerability; restrict layer-2 adjacency to trusted devices to reduce attack surface.
Cumulus Linux 5.5.0 or later
- Backup current Cumulus Linux configuration
- Download Cumulus Linux 5.5.0 or later from NVIDIA's support portal
- Upload the new image to the switch
- Install the new Cumulus Linux image using the standard upgrade procedure
- Reboot the switch to apply the new version
- Verify that neighmgrd and nlmanager services are running correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-25526 — 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-2023-25526 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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