dbcve.org
Information ExposureWeakness · CWE-200

CVE-2026-4020

HIGH · 7.5 CVSS v3.1 Published 2026-03-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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 Gravity SMTP plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 2.1.4. This is due to a REST API endpoint registered at /wp-json/gravitysmtp/v1/tests/mock-data with a permission_callback that unconditionally returns true, allowing any unauthenticated visitor to access it. When the ?page=gravitysmtp-settings query parameter is appended, the plugin's register_connector_data() method populates internal connector data, causing the endpoint to return approximately 365 KB of JSON containing the full System Report. This makes it possible for unauthenticated attackers to retrieve detailed system configuration data including PHP version, loaded extensions, web server version, document root path, database server type and version, WordPress version, all active plugins with versions, active theme, WordPress configuration details, database table names, and any API keys/tokens configured in the plugin.

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 Gravity SMTP WordPress plugin has a REST API endpoint at /wp-json/gravitysmtp/v1/tests/mock-data with a permission_callback that returns true unconditionally, allowing unauthenticated access. When the ?page=gravitysmtp-settings parameter is included, it exposes approximately 365 KB of sensitive system configuration data including PHP version, database credentials, WordPress configuration, and API keys.

MitigationUpdate to a patched version of the Gravity SMTP plugin (after 2.1.4) that fixes the unrestricted REST API endpoint, or if no patch is available, implement firewall rules or access controls to block unauthorized access to the vulnerable endpoint.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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. Identify if Gravity SMTP plugin is installed
    Navigate to WordPress admin > Plugins and look for 'Gravity SMTP' in the list of installed plugins, or check the /wp-content/plugins/ directory for a gravitysmtp folder
    Affected if The Gravity SMTP plugin appears in the installed plugins list
  2. Determine the installed plugin version
    In WordPress admin > Plugins > Installed Plugins, click on the Gravity SMTP plugin to view its version number, or inspect the main plugin PHP file header for the Version field
    Affected if The installed version is 2.1.4 or lower (versions up to and including 2.1.4 are affected)
  3. Verify the vulnerable REST API endpoint is accessible
    Send a GET request to https://yourdomain.com/wp-json/gravitysmtp/v1/tests/mock-data?page=gravitysmtp-settings using curl or a browser while NOT logged in
    Affected if The request returns a 200 OK response with JSON data containing sensitive system configuration without requiring authentication
  4. Check for sensitive data exposure in the endpoint response
    Examine the response from the previous step - look for PHP version strings, database host/username/password fields, WordPress security keys, and API keys for external services
    Affected if The response contains database credentials, WordPress configuration details, PHP version information, or third-party API keys

If the Gravity SMTP plugin version is 2.1.4 or lower AND the /wp-json/gravitysmtp/v1/tests/mock-data?page=gravitysmtp-settings endpoint returns sensitive configuration data without authentication, the environment is affected by CVE-2026-4020.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to a patched version of the Gravity SMTP plugin (after 2.1.4) that fixes the unrestricted REST API endpoint, or if no patch is available, implement firewall rules or access controls to block unauthorized access to the vulnerable endpoint.

Recommended fix Moderate confidence

Gravity SMTP version 2.1.5 or later

  1. Navigate to the WordPress admin dashboard
  2. Go to Plugins > Installed Plugins
  3. Locate the Gravity SMTP plugin
  4. Check if an update is available and update to the latest version (2.1.5 or higher)
  5. Alternatively, download the latest version from the WordPress plugin repository or from Gravity Forms' official website
  6. Verify the update was successful and the vulnerable endpoint is no longer accessible without authentication

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2026-4020 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