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Deserialization of Untrusted DataWeakness · CWE-502

CVE-2025-64353

HIGH · 8.8 CVSS v3.1 Published 2025-10-31
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 Chouby Polylang polylang allows Object Injection.This issue affects Polylang: from n/a through <= 3.7.3.

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

This is a PHP Object Injection vulnerability in the Polylang WordPress plugin caused by deserializing untrusted data. The vulnerability allows authenticated attackers (with subscriber-level access or higher) to inject arbitrary PHP objects into the application, potentially leading to code execution, SQL injection, or file manipulation through magic method exploitation.

MitigationUpdate Polylang to the latest version once a patch is released. If immediate update is not possible, implement input validation to ensure no untrusted serialized data is processed, or 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. Confirm Polylang plugin is installed
    Navigate to WordPress admin > Plugins or inspect the wp-content/plugins/polylang directory. If the plugin folder or files are present, it is installed.
    Affected if Polylang is installed and active on the WordPress site
  2. Identify installed Polylang version
    Check the plugin header in the main Polylang file (e.g., polylang.php) for the 'Version' field, or look in the WordPress plugin admin page under the Polylang listing.
    Affected if The installed version falls within the vulnerable version range for CVE-2025-64353 (compare your version to the affected ranges once published)
  3. Verify user registration is enabled
    Go to WordPress admin > Settings > General and check 'Membership: Anyone can register'. If enabled, verify if the default role is set to Subscriber or higher.
    Affected if User registration is enabled with subscriber-level or higher default role, allowing authenticated attackers to exploit the vulnerability
  4. Check for deserialization of untrusted data
    Review Polylang plugin code for uses of unserialize() that process data from user input, API requests, or HTTP parameters. Focus on endpoints that accept serialized content.
    Affected if The plugin processes untrusted serialized PHP data without proper validation, enabling PHP object injection

You are affected if Polylang is installed with a vulnerable version AND the site allows subscriber-level or higher user accounts to exist and authenticate.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update Polylang to the latest version once a patch is released. If immediate update is not possible, implement input validation to ensure no untrusted serialized data is processed, or disable the plugin until a fix is available.

Recommended fix Moderate confidence

Polylang latest version (3.7.4 or higher)

  1. 1. Backup your WordPress database and files before making any changes
  2. 2. Update the Polylang plugin to the latest available version through WordPress admin dashboard (Plugins > Polylang > Update Now)
  3. 3. Alternatively, manually download the latest Polylang plugin from wordpress.org and upload via FTP or WordPress upload
  4. 4. Verify the update was successful by checking the Plugins page shows the new version number
  5. 5. Test that multilingual functionality works correctly on your site
Caveat Review changelog for any settings or compatibility changes between your current version and the new version before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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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-2025-64353 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