Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-66055

HIGH · 7.2 CVSS v3.1 Published 2025-11-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
78/100
Remediation priority · High
Remotely reachable 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 Icegram Email Subscribers & Newsletters email-subscribers allows Object Injection.This issue affects Email Subscribers & Newsletters: from n/a through <= 5.9.10.

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

This is a deserialization vulnerability in the Icegram Email Subscribers & Newsletters WordPress plugin. The plugin improperly deserializes untrusted data, allowing authenticated attackers to inject malicious PHP objects. This type of vulnerability can lead to remote code execution, file inclusion, or other attacks via crafted serialized payloads.

MitigationUpdate the Email Subscribers & Newsletters plugin to the latest version beyond 5.9.10. If immediate updating is not possible, restrict plugin access to trusted users and monitor for suspicious serialized data in requests.

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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/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. Locate the plugin installation
    Check if the Icegram Email Subscribers plugin is installed by looking for the directory 'email-subscribers' in wp-content/plugins/ or by viewing the Plugins page in WordPress admin.
    Affected if The plugin directory or entry exists in the WordPress installation
  2. Find the installed version number
    Open the main plugin file (usually email-subscribers/email-subscribers.php) and look for the version comment header, or check the plugin details displayed on the WordPress Plugins admin page.
    Affected if The version displayed is 5.9.10 or lower (any version up to and including 5.9.10)
  3. Confirm the deserialization endpoint exists
    Review plugin code for calls to unserialize() function on user-supplied data, or check if the plugin accepts serialized data in POST/GET parameters. Common locations include any file handling, import, or settings-related functionality.
    Affected if The plugin code contains unserialize() calls processing data from request parameters without validation

You are affected if the Email Subscribers plugin is installed and the installed version is 5.9.10 or lower, and the plugin processes serialized data from untrusted sources.

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 Email Subscribers & Newsletters plugin to the latest version beyond 5.9.10. If immediate updating is not possible, restrict plugin access to trusted users and monitor for suspicious serialized data in requests.

Recommended fix Moderate confidence

Latest version of Email Subscribers & Newsletters plugin (version > 5.9.10)

  1. 1. Backup your WordPress site before making any changes.
  2. 2. Update the Email Subscribers & Newsletters plugin to the latest available version from the WordPress plugin repository.
  3. 3. Verify the update was successful by checking the installed version number.
  4. 4. Test critical email subscription workflows to ensure functionality is intact.
  5. 5. Review activity logs for any suspicious activity that may have occurred before the patch.

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

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,590
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2025-66055 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