Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-52740

HIGH · 8.8 CVSS v3.1 Published 2025-10-22
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
Deserialization of Untrusted Data vulnerability in Hernan Villanueva Boldermail boldermail allows Object Injection.This issue affects Boldermail: from n/a through <= 2.4.0.

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

The Boldermail plugin for WordPress through version 2.4.0 contains a PHP object injection vulnerability due to unsafe use of unserialize() on untrusted input. Attackers can craft malicious serialized PHP objects to potentially achieve remote code execution if magic methods exist in the application or loaded libraries.

MitigationUpdate Boldermail to the latest patched version. If no update is available, disable the plugin until a fix is released. Consider implementing input validation and replacing unserialize() with safer alternatives like json_decode().

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 Boldermail plugin is installed
    In the WordPress admin dashboard, navigate to Plugins > Installed Plugins and locate the Boldermail entry to confirm it is active on your site
    Affected if Boldermail plugin is present and active in WordPress
  2. Determine the installed Boldermail version
    View the plugin details in the WordPress plugins page to read the currently installed version number
    Affected if Version is 2.4.0 or any lower version number, indicating the plugin falls within the affected range
  3. Locate the vulnerable unserialize() call in plugin code
    Access the site files via FTP or file manager, navigate to wp-content/plugins/boldermail, and search PHP files for the pattern 'unserialize(' - examine the surrounding code to determine if untrusted input such as POST/GET parameters or database values are being passed to it
    Affected if Code contains an unserialize() call operating on data derived from user-supplied input without prior validation
  4. Assess presence of exploitable magic methods
    Search the boldermail plugin directory for magic method definitions including __destruct, __wakeup, __toString, __get, __set, or __invoke - also check other active plugins and the theme for these methods which could form a POP chain
    Affected if Any classes containing magic methods are loaded and accessible in the same PHP execution context as the vulnerable unserialize() call

You are affected if Boldermail version 2.4.0 or lower is installed AND the plugin code contains an unserialize() call operating on untrusted input, creating a potential PHP object injection vector.

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 Boldermail to the latest patched version. If no update is available, disable the plugin until a fix is released. Consider implementing input validation and replacing unserialize() with safer alternatives like json_decode().

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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Scan for this in your stack

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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-2025-52740 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
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