CpanelApplication

CVE-2020-26105

CRITICAL · 9.8 CVSS v3.1 Published 2020-09-25
Fix available
A fix is available. Upgrade to 88.0.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
In cPanel before 88.0.3, insecure chkservd test credentials are used on a templated VM (SEC-554).

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 confidence

cPanel versions before 88.0.3 use insecure default credentials for the chkservd service monitoring daemon on templated virtual machines. When cPanel is deployed from a VM template without proper generalization, the templated credentials persist across instances, allowing remote attackers to exploit these weak test credentials for service monitoring access.

MitigationUpgrade cPanel to version 88.0.3 or later. For existing deployments, regenerate all chkservd credentials and ensure VM templates are properly generalized before use (removing embedded secrets, keys, and default credentials).

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
CpanelApplication
Affected:< 88.0.3

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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 checks

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

  1. Determine installed cPanel version
    Run the command: /usr/local/cpanel/cpanel -V or check /usr/local/cpanel/version
    Affected if The displayed version is before 88.0.3 (for example, 88.0.2, 87.x.x, or earlier)
  2. Verify chkservd service is active
    Run: /scripts/chkservd -v or check system service status for chkservd
    Affected if chkservd is running and the cPanel version is below 88.0.3
  3. Inspect chkservd configuration for credentials
    Check the chkservd configuration files in /etc/chkservd.d/ or /var/cpanel/chkservd/ for any hardcoded or default credentials
    Affected if Default, templated, or weak credentials are found in the chkservd configuration files
  4. Check for VM template deployment
    Review system documentation or cloud-init logs to determine if this cPanel instance was deployed from a pre-built VM template
    Affected if The system was deployed from a VM template and the cPanel version is before 88.0.3

You are affected if cPanel version is below 88.0.3 AND chkservd is running with templated/default credentials from a VM image deployment.

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 88.0.3 or later
Fixed in 88.0.3
Interim mitigation

Upgrade cPanel to version 88.0.3 or later. For existing deployments, regenerate all chkservd credentials and ensure VM templates are properly generalized before use (removing embedded secrets, keys, and default credentials).

Recommended fix High confidence

cPanel 88.0.3 or later

  1. Create a full backup of the cPanel server before proceeding with any upgrade
  2. Ensure adequate disk space and system resources are available for the upgrade
  3. Run the update command via terminal: /usr/local/cpanel/scripts/upcp --force
  4. Alternatively, use WHM interface: Home >> cPanel >> Upgrade to Latest Version
  5. Allow the upgrade process to complete fully without interruption
  6. Verify the cPanel version after upgrade: grep CPANEL /etc/cpanel.config or whmapi1 version
  7. Confirm the chkservd service is running properly: /scripts/restartsrv_chkservd
  8. Review cPanel logs to ensure no errors occurred during upgrade: /var/log/cpanel-up.log
Caveat Standard cPanel upgrade risks apply - review release notes for your specific version for any configuration or feature changes

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

Fix this in Cpanel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-26105 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-26105 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