Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-54806

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-17
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 WP Activity Log <= 5.6.3.1 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

Unauthenticated PHP Object Injection vulnerability in the WP Activity Log WordPress plugin versions 5.6.3.1 and below. The plugin deserializes untrusted input without proper sanitization, allowing remote attackers to inject malicious PHP objects and potentially achieve arbitrary code execution through magic method invocation.

MitigationUpdate WP Activity Log plugin to the latest patched version immediately. If no update is available, disable the plugin or implement web application firewall rules to block requests to vulnerable endpoints.

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. Locate the WP Activity Log plugin installation
    Check the /wp-content/plugins/ directory for the 'wp-security-audit-log' or 'wp-activity-log' folder, or use WP-CLI: wp plugin list --name='wp-activity-log'
    Affected if The plugin folder is missing from the plugins directory, indicating the plugin is not installed
  2. Determine the installed version
    Check the plugin's main PHP file (usually within the plugin folder) for the 'Version' header in the plugin comment block, or run: wp plugin get wp-security-audit-log --format=json
    Affected if The version returned is 5.6.3.1 or lower, placing it within the affected range
  3. Verify the plugin is active
    Run: wp plugin list --status=active --name='wp-activity-log' or check via WordPress admin dashboard under Plugins
    Affected if The plugin appears in the active plugins list and responds to requests, meaning the vulnerable code is loaded into memory
  4. Identify the vulnerable unserialize call location
    Search the plugin source code for 'unserialize' function calls, particularly those processing $_GET, $_POST, $_REQUEST, or $_COOKIE parameters without sanitization. Common patterns: unserialize($_REQUEST['...'])
    Affected if An active unserialize() call is found that processes untrusted input from HTTP request parameters without validation or sanitization

You are affected if the WP Activity Log plugin is installed, active, version 5.6.3.1 or lower, and contains the vulnerable unserialize() call processing untrusted input.

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 WP Activity Log plugin to the latest patched version immediately. If no update is available, disable the plugin or implement web application firewall rules to block requests to vulnerable endpoints.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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Scan for this in your stack

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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-2026-54806 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