CVE-2026-20099
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 web-based management interface of Cisco FXOS Software and Cisco UCS Manager Software could allow an authenticated, local attacker with administrative privileges to perform command injection attacks on an affected system and elevate privileges to root. This vulnerability is due to insufficient input validation of command arguments supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to the affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system of the affected device with root-level privileges.
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 confidenceCommand injection vulnerability in Cisco FXOS and UCS Manager web-based management interface allows authenticated administrators to inject arbitrary OS commands through insufficiently validated command arguments, achieving root-level execution.
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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/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 installed product and versionAccess the device CLI and run 'show version' or access the web management interface login page to identify if the system is running Cisco FXOS or Cisco UCS Manager. Note the exact software version displayed.Affected if The system runs Cisco FXOS or Cisco UCS Manager and the version is within the affected range (if known) or unpatched.
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Confirm web-based management interface is enabledCheck device configuration for http or https server settings. In CLI, use 'show running-config | include http' or similar command to see if the web interface is active.Affected if The web-based management interface is enabled and accessible, providing the attack surface for this vulnerability.
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Verify admin account integrityList all administrative accounts using 'show admin users' or similar command in the management interface. Check for unexpected accounts or privilege escalation from standard admin to root.Affected if Unexpected administrative accounts exist or privilege escalation to root has occurred without documented authorization.
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Review logs for suspicious command executionExamine system logs, audit logs, and command history for entries containing unusual or unexpected OS commands, especially those indicating shell escape or root-level operations initiated from the web interface.Affected if Logs contain commands or logs showing execution of arbitrary OS commands that were not initiated by authorized administrative actions.
The environment is affected if it runs Cisco FXOS or UCS Manager with the web-based management interface enabled and shows evidence of unauthorized root-level command execution or unexpected administrative changes.
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 Cisco-provided patches for FXOS and UCS Manager software; restrict administrative access and monitor for unauthorized privilege escalation attempts.
- Consultation8.0 h
- Implementation12.0 h
- Testing8.0 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 $9,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20099 — 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-2026-20099 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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