Thousandeyes Virtual ApplianceApplication · Cisco
CVE-2026-20199
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 vulnerability in the SSL certificate handling of Cisco ThousandEyes Virtual Appliance could allow an authenticated, remote attacker to execute commands on the underlying operating system as the root user. This vulnerability is due to insufficient validation of user-supplied input. An authenticated attacker could exploit this vulnerability by uploading a crafted certificate to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system. To exploit this vulnerability, the attacker must have valid administrative credentials.
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 confidenceThe vulnerability exists in the SSL certificate handling component of Cisco ThousandEyes Virtual Appliance. An authenticated attacker with valid administrative credentials can upload a crafted certificate that lacks proper input validation, enabling arbitrary code execution with root privileges on the underlying operating system.
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
Thousandeyes Virtual ApplianceApplication
< 0.262.0CVSS 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
- Network
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/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 if Cisco ThousandEyes Virtual Appliance is deployedLocate the virtual appliance in your environment inventory or scan network for ThousandEyes servicesAffected if The system is a Cisco ThousandEyes Virtual Appliance instance
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Determine the installed ThousandEyes Virtual Appliance versionAccess the appliance admin interface and navigate to System Settings > About, or run 'te-agent --version' if CLI access is availableAffected if The version number displayed is below 0.262.0 (e.g., 0.261.0, 0.260.0, etc.)
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Verify if the SSL certificate management feature is accessibleLog into the ThousandEyes admin portal and navigate to Settings > SSL Certificate or equivalent certificate upload sectionAffected if The certificate upload interface is available and accepting input
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Confirm administrative access is possibleCheck if administrative credentials exist for the ThousandEyes appliance, or review access control lists for the admin interfaceAffected if An authenticated administrator account can access the certificate upload functionality
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Audit for recent certificate uploadsReview ThousandEyes appliance logs, system logs, or the certificate storage directory for any certificate files uploaded around the time of potential compromiseAffected if Unexpected or unauthorized certificate files are present, or certificate upload events are found in logs from untrusted sources
The environment is affected if it runs Cisco ThousandEyes Virtual Appliance version 0.262.0 or lower AND has the admin interface with certificate upload feature accessible to authenticated users.
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 · scoped0.262.0
Restrict administrative access to trusted personnel only and apply the vendor-provided patch when available. Until the patch is applied, monitor administrative certificate upload activities closely.
Cisco ThousandEyes Virtual Appliance version 0.262.0 or later
- 1. Back up the current ThousandEyes Virtual Appliance configuration and any SSL certificates
- 2. Obtain the fixed version 0.262.0 or later from Cisco's official download portal (sec.cloudapps.cisco.com)
- 3. Upload the upgrade package to the Virtual Appliance through the admin interface or CLI
- 4. Apply the upgrade following Cisco's standard ThousandEyes Virtual Appliance upgrade procedure
- 5. Verify the upgrade was successful by checking the version number in the admin interface
- 6. Re-apply any custom SSL certificates as needed after the upgrade
- 7. Confirm the appliance is functioning normally and agents are reporting data
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Thousandeyes Virtual Appliance
Scoped from the published advisory
- 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-2026-20199 — 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-2026-20199 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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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