CVE-2018-20863
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 · uneditedcPanel before 76.0.8 allows remote attackers to execute arbitrary code via mailing-list attachments (SEC-452).
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 confidencecPanel before version 76.0.8 contains a vulnerability in its mailing-list attachment handling functionality that allows unauthenticated remote attackers to execute arbitrary code by sending specially crafted attachments through mailing-list features.
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< 76.0.8CVSS 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:3.0/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 checksWork through these to decide whether this CVE applies to you.
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Verify cPanel is installedCheck for cPanel processes or binaries on the system. Common indicators include the presence of /usr/local/cpanel/ directory or cPanel-related services running.Affected if cPanel software is present on the server
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Determine installed cPanel versionRun the command to retrieve the cPanel version. On the command line, you can typically check /usr/local/cpanel/version or use cPanel's internal tools to fetch the current version string.Affected if The installed version string is lower than 76.0.8
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Confirm mailing-list functionality is accessibleCheck if mailing-list features are enabled on the cPanel instance. This may involve reviewing the feature manager settings or checking if mailing-list creation interfaces are available to users.Affected if Mailing-list functionality is enabled and accessible to users
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Verify attachment handling is availableConfirm that the mailing-list attachment upload feature is operational. This is typically available through the mailing-list creation or management interface in cPanel.Affected if Users can create mailing lists with attachments enabled
You are affected if cPanel is installed, the version is below 76.0.8, and mailing-list functionality with attachments is enabled on your server.
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 · scoped76.0.8
Upgrade cPanel to version 76.0.8 or later. If immediate upgrade is not possible, consider disabling or restricting mailing-list functionality as a temporary workaround.
cPanel 76.0.8 or later (preferably latest stable release)
- 1. Back up the cPanel configuration and all critical data before performing the upgrade
- 2. Access the cPanel server via SSH as root or use the cPanel update interface
- 3. Run the cPanel update command: /scripts/upcp --force or use the WebHost Manager (WHM) interface to check for updates
- 4. Ensure the cPanel version is updated to 76.0.8 or later
- 5. Verify the update was successful by checking the cPanel version: whmapi1 version
- 6. Test that mailing-list attachment functionality works correctly after the update
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-20863 — 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-2018-20863 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