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CpanelApplication

CVE-2020-26104

HIGH · 7.5 CVSS v3.1 Published 2020-09-25
Fix available
A fix is available. Upgrade to 88.0.3 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
In cPanel before 88.0.3, an insecure SRS secret is used on a templated VM (SEC-552).

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 before version 88.0.3 uses an insecure (weak, default, or predictable) SRS (Sender Rewriting Scheme) secret on templated virtual machine images. SRS is used to preserve sender reputation in email forwarding; an insecure secret could allow attackers to manipulate email headers or impersonate senders.

MitigationUpgrade cPanel to version 88.0.3 or later. For existing templated VMs, regenerate the SRS secret to ensure it is unique and cryptographically strong.

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
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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. Check installed cPanel version
    Run `/usr/local/cpanel/cpanel -V` or `whmapi1 get_cpanel_version` and compare the reported version number to 88.0.3
    Affected if The reported version is less than 88.0.3
  2. Verify SRS is enabled
    Check if the Sender Rewriting Scheme feature is active in the cPanel configuration, typically found in the SRS settings or email routing configuration
    Affected if SRS is enabled and the cPanel version is below 88.0.3
  3. Locate the SRS secret file
    Inspect the SRS configuration directory (commonly /var/cpanel/srs or the equivalent configuration path) and locate the secret file used for SRS encryption
    Affected if The secret file contains a default, weak, or predictable value rather than a unique cryptographically strong secret
  4. Compare SRS secret to known defaults
    Examine the SRS secret value for patterns indicating default or weak secrets (such as simple strings, sequential patterns, or well-known test values)
    Affected if The secret matches a known default pattern or is weak/predictable

A user is affected if their cPanel installation is version 88.0.3 or lower, SRS is enabled, and the SRS secret is a default or weak value rather than a unique strong secret.

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 88.0.3 or later
Fixed in 88.0.3
Interim mitigation

Upgrade cPanel to version 88.0.3 or later. For existing templated VMs, regenerate the SRS secret to ensure it is unique and cryptographically strong.

Fix this in Cpanel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

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-2020-26104 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