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Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-39495

CRITICAL · 9.8 CVSS v3.1 Published 2025-05-23
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 BoldThemes Avantage avantage allows Object Injection.This issue affects Avantage: from n/a through <= 2.4.9.

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 BoldThemes Avantage theme allows attackers to deserialize untrusted data, potentially leading to remote code execution if suitable gadget chains exist in the application or installed plugins. The vulnerability stems from unsafe use of PHP's unserialize() function on data from an unknown source.

MitigationUpdate the Avantage theme to the latest version once available, or remove the theme if not in use. Until a patch is released, investigate and sanitize any user-supplied data being passed to unserialize() calls.

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 Avantage theme is installed
    Check your WordPress installation under Appearance > Themes or inspect the /wp-content/themes/ directory for the 'avantage' folder. Also check if the theme is currently active.
    Affected if The Avantage theme by BoldThemes is present in the themes directory and is activated on the site.
  2. Identify installed theme version
    Open the theme's style.css file located at /wp-content/themes/avantage/style.css and locate the 'Version:' header in the file comments, or check the theme admin panel under Appearance > Themes for version information.
    Affected if The installed version does not match or is lower than the patched version (once released). Compare against the vendor's release notes.
  3. Locate unsafe unserialize() calls
    Search the theme's PHP files for uses of unserialize() by scanning files in /wp-content/themes/avantage/ using 'grep -r "unserialize" .' or reviewing core files like functions.php and any files handling user input or AJAX endpoints.
    Affected if Code contains unserialize() calls processing data from user-supplied sources (request parameters, cookies, POST/GET inputs).
  4. Determine if user input reaches unserialize
    Trace the data flow from the unserialize() call backward to identify if any HTTP request parameters (GET, POST, COOKIE, or custom headers) are passed to it without sanitization. Review AJAX handlers and callback functions in the theme.
    Affected if Untrusted user-controlled data (request parameters, cookies, or external inputs) flows into the unserialize() function without validation.
  5. Assess gadget chain availability
    Review installed plugins and other themes for PHP classes that could serve as gadget chains. Check if common plugin families known to contain gadget chains (like certain WooCommerce, Jetpack, or popular plugin versions) are active alongside this theme.
    Affected if Plugins or other components with exploitable gadget chains are installed, enabling RCE when combined with the unserialize() vulnerability.

You are affected if the BoldThemes Avantage theme is installed, contains the vulnerable unserialize() code path, and user-supplied input can reach that function without sanitization.

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 Avantage theme to the latest version once available, or remove the theme if not in use. Until a patch is released, investigate and sanitize any user-supplied data being passed to unserialize() calls.

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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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-2025-39495 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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