dbcve.org
Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-48336

CRITICAL · 9.8 CVSS v3.1 Published 2025-05-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Deserialization of Untrusted Data vulnerability in ThimPress Course Builder course-builder allows Object Injection.This issue affects Course Builder: from n/a through < 3.6.6.

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

This is a PHP Object Injection vulnerability in the ThimPress Course Builder WordPress plugin. The plugin deserializes untrusted data without proper validation, allowing attackers to inject and instantiate arbitrary PHP objects. This can potentially lead to remote code execution if suitable 'POP chains' (Property Oriented Programming chains) exist within the application or installed plugins.

MitigationUpgrade to Course Builder version 3.6.6 or later, which contains the patch for this deserialization vulnerability. If immediate updating is not possible, consider disabling the plugin until the patch can be applied.

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
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. Confirm Course Builder plugin is installed
    In WordPress admin, go to Plugins > Installed Plugins and look for 'ThimPress Course Builder' or 'LearnPress' (the plugin may also be listed under this name). Check if it is activated.
    Affected if The plugin is installed and activated in WordPress.
  2. Identify installed version number
    In WordPress admin, go to Plugins > Installed Plugins. Click on the Course Builder/LearnPress plugin to view details, or check the plugin header in /wp-content/plugins/learnpress/ or /wp-content/plugins/thim-course-builder/ for the 'Version' comment. Alternatively, open the main plugin PHP file and look for the 'Version' defined in the plugin header comment.
    Affected if The installed version is lower than 3.6.6.
  3. Verify deserialization is reachable
    Review plugin code for calls to unserialize() on user-supplied input (typically $_GET, $_POST, $_COOKIE, or REST API parameters). Common patterns: unserialize($_POST['data']), unserialize($_REQUEST['object']), or similar. Check any AJAX endpoints, public-facing forms, or REST routes handled by the plugin.
    Affected if The plugin code contains unserialize() calls processing untrusted input without prior sanitization.
  4. Check for signs of exploitation attempts
    Review web server access logs for unusual PHP object patterns in request parameters (e.g., serialized payloads like O: or a:). Check for new or modified PHP files in the plugin directory /wp-content/plugins/learnpress/ or /wp-content/uploads/ that may indicate successful object injection leading to file creation.
    Affected if Log analysis reveals serialized PHP object payloads in requests to the site, or unexpected PHP files exist in plugin or upload directories.

You are affected if the ThimPress Course Builder/LearnPress plugin is installed with a version lower than 3.6.6 and the vulnerable deserialization code is accessible or has been exploited.

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

Upgrade to Course Builder version 3.6.6 or later, which contains the patch for this deserialization vulnerability. If immediate updating is not possible, consider disabling the plugin until the patch can be applied.

Recommended fix Moderate confidence

3.6.6

  1. Backup your WordPress site before making any changes
  2. Navigate to WordPress admin dashboard > Plugins
  3. Locate the Course Builder (course-builder) plugin by ThimPress
  4. Update the plugin to version 3.6.6 or the latest available version
  5. Verify the update was successful by checking the installed version number

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2025-48336 in production — separate from our analysis above.

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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
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