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Nexus DashboardApplication · Cisco

CVE-2026-20042

MEDIUM · 6.5 CVSS v3.1 Published 2026-04-01
Fix available
A fix is available. Upgrade to 4.2.1 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 · unedited
A vulnerability in the configuration backup feature of Cisco Nexus Dashboard could allow an attacker who has the encryption password and access to Full or Config-only backup files to access sensitive information. This vulnerability exists because authentication details are included in the encrypted backup files. An attacker with a valid backup file and encryption password from an affected device could decrypt the backup file. The attacker could then use the authentication details in the backup file to access internal-only APIs on the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system as the root user.

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 confidence

The Cisco Nexus Dashboard configuration backup feature stores authentication credentials in encrypted backup files. An attacker who obtains both a valid backup file (Full or Config-only) and the encryption password can decrypt the backup, extract stored credentials, and use them to access internal-only APIs on the affected device. This allows the attacker to execute arbitrary commands as root on the underlying operating system.

MitigationApply the Cisco patch when released. In the interim, strictly control access to backup files and encryption passwords, rotate passwords immediately if compromised, and monitor for unauthorized access to backup storage.

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
Nexus DashboardApplication
Affected:< 4.2.1

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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Cisco Nexus Dashboard version
    Access the Nexus Dashboard admin UI or use the CLI command 'show version' to retrieve the installed software version.
    Affected if The installed version is lower than 4.2.1 (e.g., 4.2.0, 4.1.x, earlier releases).
  2. Locate configuration backup files
    Navigate to the backup storage location (typically /backup or a designated NFS/export path) and list all backup files (.bak or .tar.gz extensions) created by the backup feature.
    Affected if Any backup files (Full or Config-only) exist on the system or attached storage.
  3. Verify backup file permissions
    Use 'ls -la' on backup files to inspect owner, group, and world-readable permissions. Check if unauthorized users or groups can read these files.
    Affected if Backup files are readable by users other than the intended administrator account (world-readable or group-readable with broad membership).
  4. Assess encryption password access controls
    Review who has knowledge of or access to the backup encryption password. Check if the password is stored in plain text in scripts, config files, or shared documentation.
    Affected if The encryption password is stored insecurely, shared with unauthorized personnel, or accessible beyond the limited admin team.

A user is affected if their Cisco Nexus Dashboard version is below 4.2.1 AND they have backup files and encryption passwords that could be accessed by an attacker.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 4.2.1 or later
Fixed in 4.2.1
Interim mitigation

Apply the Cisco patch when released. In the interim, strictly control access to backup files and encryption passwords, rotate passwords immediately if compromised, and monitor for unauthorized access to backup storage.

Recommended fix High confidence

Cisco Nexus Dashboard 4.2.1 or later

  1. Upgrade Cisco Nexus Dashboard to version 4.2.1 or later to remediate this vulnerability
  2. After upgrading, regenerate all existing backup files created with versions prior to 4.2.1 using the new version
  3. Rotate the encryption passwords used for backups after the upgrade
  4. Review audit and access logs for any signs of unauthorized access using compromised backup files
  5. If you suspect exposure, rotate all credentials and API keys that may have been included in backup files
Caveat Review Cisco Nexus Dashboard 4.2.1 release notes for any compatibility changes or migration requirements before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Nexus Dashboard Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,970
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,152.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20042 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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