dbcve.org
Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-49765

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-15
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
Unauthenticated PHP Object Injection in Integration for Mailchimp and Contact Form 7, WPForms, Elementor, Ninja Forms <= 1.1.8 versions.

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

An unauthenticated PHP Object Injection vulnerability exists in the WordPress plugin 'Integration for Mailchimp and Contact Form 7, WPForms, Elementor, Ninja Forms' versions 1.1.8 and below. The flaw allows remote attackers to inject malicious serialized PHP objects via untrusted input processed by the plugin, potentially triggering magic methods to achieve arbitrary code execution.

MitigationUpdate the plugin to version 1.1.9 or later immediately; if no patched version is available, disable the plugin entirely and consider alternative form integration solutions.

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. Identify if the vulnerable plugin is installed
    Access your WordPress site via FTP or file manager and check the /wp-content/plugins/ directory for a folder related to Mailchimp and Contact Form 7 integration. Common folder names include 'mc4wp', 'mailchimp-for-cf7', or similar. Alternatively, log into WordPress admin and navigate to Plugins to list all installed plugins.
    Affected if The plugin 'Integration for Mailchimp and Contact Form 7, WPForms, Elementor, Ninja Forms' or a similarly named Mailchimp integration plugin is found in the plugins directory.
  2. Determine the installed plugin version
    If the plugin is installed, locate its main PHP file (usually named similarly to the plugin folder, e.g., index.php or a file containing the plugin header). Open the file and look for a comment block containing 'Version: x.x.x' or check the WordPress admin Plugins page for the installed version.
    Affected if The installed version is 1.1.8 or any version lower than 1.1.8.
  3. Verify the plugin is active
    Log into WordPress admin and go to Plugins > Installed Plugins. Check if the Mailchimp integration plugin is currently activated.
    Affected if The plugin is activated and running version 1.1.8 or below.
  4. Check for signs of exploitation attempts
    Review your web server access logs (typically found in /logs/ or /access_logs/) for unusual POST requests to endpoints that may be handled by the plugin. Look for serialized PHP object patterns in request bodies, such as 'O:','a:','s:' followed by numbers, or base64-encoded strings containing these patterns.
    Affected if Suspicious serialized data or object injection patterns are found in HTTP requests targeting the plugin.

You are affected if the plugin is installed, activated, and running version 1.1.8 or below.

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 the plugin to version 1.1.9 or later immediately; if no patched version is available, disable the plugin entirely and consider alternative form integration solutions.

Recommended fix Moderate confidence

Version 1.1.9 or later of the Mailchimp integration plugin for Contact Form 7/WPForms/Elementor/Ninja Forms

  1. Identify the specific plugin: This vulnerability affects an integration plugin that connects Mailchimp with Contact Form 7, WPForms, Elementor, or Ninja Forms. Check your WordPress installation for any such integration plugin.
  2. Locate the affected plugin in your WordPress site via wp-admin > Plugins or via FTP/SFTP access.
  3. Verify the currently installed version of the plugin.
  4. Upgrade the plugin to version 1.1.9 or later, which contains the security fix for the unauthenticated PHP object injection vulnerability.
  5. After upgrading, confirm the new version is active and the site functions normally.
  6. Review activity logs to check for any indicators of exploitation attempts prior to the patch.
Caveat Minor: Review plugin settings after upgrade to confirm all Mailchimp integrations continue functioning as expected

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

Have this fixed Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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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-2026-49765 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