Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-67911

CRITICAL · 9.8 CVSS v3.1 Published 2026-01-08
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 Tribulant Software Newsletters newsletters-lite allows Object Injection.This issue affects Newsletters: from n/a through <= 4.11.

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 PHP Object Injection vulnerability in the Tribulant Newsletters WordPress plugin caused by unsafe deserialization of untrusted data. The flaw allows remote attackers to inject malicious PHP objects, potentially leading to remote code execution, depending on available gadget chains in the application environment.

MitigationUpdate the Newsletters plugin to the latest patched version immediately. As an interim measure, consider deploying a WAF rule to block deserialization-related payloads and disable the plugin if no patch is available.

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. Verify the Tribulant Newsletters plugin is installed
    Go to WordPress Admin > Plugins and look for 'Newsletters' by Tribulant in the list of active plugins
    Affected if The plugin is installed and active
  2. Check the installed plugin version
    In WordPress Admin > Plugins > Installed Plugins, click on the Newsletters plugin to view its version number. Compare this to the version in the vendor's security advisory
    Affected if The installed version is older than the patched version listed in the plugin's changelog or security release notes
  3. Identify if the plugin's subscription form endpoint is exposed
    Check if your site exposes the subscription form at /?na= or /wp-json/tribulant-newsletters/v1/subscribe or similar endpoints used by the plugin
    Affected if The subscription endpoint is publicly accessible without additional authentication
  4. Inspect server logs for deserialization-related errors
    Review Apache/Nginx error logs and PHP error logs for notices containing 'unserialize', 'Object injection', or similar PHP warnings related to the newsletters plugin
    Affected if Unserialize errors or PHP object injection warnings appear in logs pointing to the newsletters plugin
  5. Check for unexpected PHP files in the uploads directory
    Look in wp-content/uploads/ and subdirectories for newly created PHP files with suspicious names or base64-encoded content that were not uploaded intentionally
    Affected if Unknown PHP files exist in uploads that you did not deliberately place there

You are affected if the Newsletters plugin is installed, the version is older than the patched release, and the subscription functionality is publicly accessible.

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

Update the Newsletters plugin to the latest patched version immediately. As an interim measure, consider deploying a WAF rule to block deserialization-related payloads and disable the plugin if no patch is available.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,780
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-67911 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2025-67911 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