Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-42687

HIGH · 8.1 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 →
90/100
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 EventPrime <= 4.3.2.1 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 · moderate confidence

Unauthenticated PHP Object Injection vulnerability in the EventPrime WordPress plugin versions 4.3.2.1 and below allows remote attackers to inject malicious PHP objects via unserialization of user-controlled input, potentially leading to remote code execution through PHP magic methods and available gadget chains.

MitigationUpgrade EventPrime to the latest version (beyond 4.3.2.1) which should contain a fix replacing vulnerable unserialize() calls with secure alternatives like json_decode(), or implement input validation and sanitization at the application layer.

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

CVSS:3.1/AV:N/AC:H/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 EventPrime plugin is installed
    In WordPress admin, go to Plugins > Installed Plugins and look for 'EventPrime' or check the wp-content/plugins/event-prime/ directory for the plugin folder
    Affected if EventPrime plugin is present on the WordPress site
  2. Check installed EventPrime version
    In WordPress admin, view the plugin details to see the version number, or inspect the main plugin file header in wp-content/plugins/event-prime/event-prime.php for the 'Version' field
    Affected if The version number is 4.3.2.1 or lower (any version at or below 4.3.2.1)
  3. Locate vulnerable unserialize() calls
    Search the EventPrime plugin files for 'unserialize' function calls, particularly looking in files that handle request parameters or user input (e.g., $_GET, $_POST, $_REQUEST)
    Affected if Code contains unserialize() calls that process user-supplied input without sanitization
  4. Verify exposed attack surface
    Identify if any AJAX endpoints or public-facing forms handled by EventPrime accept serialized data that reaches the vulnerable unserialize() calls
    Affected if User-controlled data from unauthenticated requests reaches an unserialize() call within the plugin

A WordPress site is affected if it runs EventPrime plugin version 4.3.2.1 or lower AND the plugin processes untrusted serialized input through vulnerable unserialize() calls accessible to unauthenticated users.

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

Upgrade EventPrime to the latest version (beyond 4.3.2.1) which should contain a fix replacing vulnerable unserialize() calls with secure alternatives like json_decode(), or implement input validation and sanitization at the application layer.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2026-42687 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