CVE-2026-22321
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 · uneditedA stack-based buffer overflow in the device's Telnet/SSH CLI login routine occurs when a unauthenticated attacker send an oversized or unexpected username input. An overflow condition crashes the thread handling the login attempt, forcing the session to close. Because other CLI sessions remain unaffected, the impact is limited to a low‑severity availability disruption.
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 confidenceA stack-based buffer overflow vulnerability exists in the device's Telnet/SSH CLI login routine. When an unauthenticated attacker sends an oversized or unexpectedly formatted username input, the buffer overflow crashes the thread handling the login attempt, forcing the session to close. Other CLI sessions remain unaffected, limiting the impact to localized availability disruption.
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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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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Confirm Telnet service is exposedCheck if port 23 (Telnet) is open and listening on the device using 'netstat -an | grep :23' or a network port scannerAffected if Telnet service is enabled and accessible over the network
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Confirm SSH service is exposedCheck if port 22 (SSH) is open and listening on the device using 'netstat -an | grep :22' or an SSH client connection testAffected if SSH service is enabled and accessible over the network
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Determine installed firmware/software versionRun 'show version' or access the device management interface to retrieve the current firmware or software version numberAffected if The installed version matches or falls within the affected version range (compare to vendor advisory)
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Verify unauthenticated CLI login is possibleAttempt to connect to Telnet or SSH without providing credentials - observe if the login prompt accepts input before authenticationAffected if The device presents a username prompt or accepts input prior to successful authentication
The environment is affected if Telnet or SSH is enabled and accessible, and the installed version falls within the affected range, since an unauthenticated user can trigger the buffer overflow via oversized username input at the login prompt.
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.
From vendor dataApply vendor-supplied firmware/software patches that implement proper input length validation and bounds checking in the CLI login routine. As an interim control, restrict Telnet/SSH access to trusted IP addresses via firewall rules.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-22321 — 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-2026-22321 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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- Version or environment caveats, and links to real fixes
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