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Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-39478

HIGH · 8.8 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 →
94/100
Remediation priority · Urgent
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
Contributor PHP Object Injection in Anti-Malware Security and Brute-Force Firewall <= 4.23.87 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 · moderate confidence

PHP Object Injection vulnerability in the Anti-Malware Security and Brute-Force Firewall WordPress plugin (versions <= 4.23.87) allows contributor-level authenticated users to potentially execute arbitrary PHP code via unsafe deserialization of user-supplied data.

MitigationUpdate the plugin to the latest version (above 4.23.87) to obtain the vendor patch that addresses the unsafe deserialization, or if unable to update, disable the plugin until a fix 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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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 Anti-Malware Security plugin is installed
    Check your WordPress installation under wp-content/plugins/ for a folder containing 'anti-malware' or 'brute-force' in the name, or use WP-CLI: wp plugin list --status=active --format=csv
    Affected if The plugin folder exists in wp-content/plugins/
  2. Determine the installed plugin version
    Open the main PHP file in the plugin folder and look for the 'Version:' header in the plugin comment block, or query: SELECT option_value FROM wp_options WHERE option_name LIKE '%plugin_version%'
    Affected if The version number shown is 4.23.87 or lower
  3. Verify the plugin is active on the site
    Use WP-CLI: wp plugin status anti-malware-security (or relevant folder name), or check in WordPress admin under Plugins > Installed Plugins
    Affected if The plugin shows as 'Active' or 'Enabled'
  4. Check if contributor-level or lower user accounts exist
    In WordPress admin, go to Users > All Users and review the Role column, or query: SELECT user_id, meta_value FROM wp_usermeta WHERE meta_key = 'wp_capabilities'
    Affected if Any user has the 'contributor' role (or any role below author) and the plugin is active at version 4.23.87 or lower

You are affected if the Anti-Malware Security and Brute-Force Firewall plugin is active at version 4.23.87 or lower and your site has any user with contributor-level access or lower.

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 plugin to the latest version (above 4.23.87) to obtain the vendor patch that addresses the unsafe deserialization, or if unable to update, disable the plugin until a fix is available.

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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

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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-2026-39478 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