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CpanelApplication

CVE-2020-26112

HIGH · 7.5 CVSS v3.1 Published 2020-09-25
Fix available
A fix is available. Upgrade to 90.0.10 or later.
See remediation →
84/100
Remediation priority · High
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
The email quota cache in cPanel before 90.0.10 allows overwriting of files.

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

The email quota cache functionality in cPanel versions before 90.0.10 contains a file overwrite vulnerability, likely due to insufficient path validation in the cache mechanism. This allows an attacker to potentially overwrite arbitrary files on the server through the quota cache system.

MitigationUpdate cPanel to version 90.0.10 or later to patch the file overwrite vulnerability in the email quota cache.

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:< 90.0.10

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
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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. Determine the installed cPanel version
    Run the command: /usr/local/cpanel/cpanel -V or check WHM > Server Information > cPanel version
    Affected if The version shown is below 90.0.10 (for example, 89.0.0, 88.0.5, etc.)
  2. Verify the email subsystem is enabled
    Check if email accounts exist on the server: grep '^EMAIL' /var/cpanel/accounting* or list email accounts via cPanel API
    Affected if Email accounts or email service is active on the server, as the quota cache is only relevant when email is configured
  3. Locate the email quota cache directory
    Check for the presence of quota cache files in /var/cpanel/email/quota/ or similar cache directories under /var/cpanel/
    Affected if Quota cache directory exists and contains files, indicating the vulnerable cache mechanism is in use
  4. Review permissions on the quota cache directory
    Run: ls -la /var/cpanel/email/quota/ or ls -la /var/cpanel/email/ to inspect directory permissions and ownership
    Affected if The cache directory is writable by the cPanel user or lacks proper path validation safeguards (world-writable or owned by untrusted user)

A server is affected if it runs any cPanel version below 90.0.10 and has the email quota cache functionality active (email accounts or service enabled).

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.

From vendor data
Upgrade available Upgrade to 90.0.10 or later
Fixed in 90.0.10
Interim mitigation

Update cPanel to version 90.0.10 or later to patch the file overwrite vulnerability in the email quota cache.

Fix this in Cpanel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

Scan for this in your stack

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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-2020-26112 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