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DrupalCMS

CVE-2026-6366

MEDIUM · 6.6 CVSS v3.1 Published 2026-05-19
Fix available
A fix is available. Upgrade to 10.5.9 / 10.6.7 or later.
See remediation →
72/100
Remediation priority · Elevated
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
Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in Drupal Drupal core allows Object Injection. This issue affects Drupal core: from 8.0.0 before 10.5.9, from 10.6.0 before 10.6.7, from 11.0.0 before 11.2.11, from 11.3.0 before 11.3.7.

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

This is a PHP object injection vulnerability in Drupal core caused by improper validation of dynamically-determined object attributes. Attackers can exploit this by injecting malicious serialized objects, potentially achieving remote code execution through PHP's object instantiation mechanism.

MitigationUpgrade Drupal core to the patched versions (10.5.9, 10.6.7, 11.2.11, or 11.3.7) and audit custom/contrib modules for insecure unserialize() calls handling user input.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
DrupalCMS
Affected:>= 8.0.0, < 10.5.9>= 10.6.0, < 10.6.7>= 11.0.0, < 11.2.11>= 11.3.0, < 11.3.7

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

CVSS:3.1/AV:N/AC:H/PR:H/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. Determine installed Drupal core version
    Run 'drush status' or check the 'VERSION' constant in core/lib/Drupal.php, or view the CHANGELOG.txt file in the Drupal root directory
    Affected if The installed version falls within < 10.5.9, >= 10.6.0 and < 10.6.7, >= 11.0.0 and < 11.2.11, or >= 11.3.0 and < 11.3.7
  2. Identify custom or contributed modules using PHP unserialize()
    Search the codebase for 'unserialize(' calls using: grep -r "unserialize(" --include="*.php" /path/to/web/modules/custom /path/to/web/modules/contrib
    Affected if Any module uses unserialize() with data derived from user request parameters, form input, or external API responses
  3. Check for dynamic attribute modification patterns
    Search for code using __set, __get magic methods, or dynamic property assignment such as $object->$key = $value where $key originates from user input
    Affected if Code allows user-controlled keys to modify object properties that could reach deserialization functions
  4. Review Symfony component versions if using custom serialization
    Check composer.lock for symfony/var-dumper and symfony/yaml versions used by Drupal, and examine any custom code invoking unserialize() or yaml_parse()
    Affected if Custom code passes serialized data to unserialize() without using a signed serializer or the Drupal-safe serializer
  5. Audit PHP runtime configuration for deserialization
    Review php.ini settings: unserialize_callback_func should be set, and allow_url_include should be disabled. Check if any debug or development modules expose serialized data in URLs
    Affected if PHP is configured loosely around deserialization or debug endpoints leak serialized object data

Your environment is affected if you run any Drupal version below 10.5.9, 10.6.7, 11.2.11, or 11.3.7 AND your codebase or installed modules accept serialized data from untrusted sources.

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
Upgrade available Upgrade to 10.5.9 / 10.6.7 / 11.2.11 or later
Fixed in 10.5.910.6.711.2.11
Interim mitigation

Upgrade Drupal core to the patched versions (10.5.9, 10.6.7, 11.2.11, or 11.3.7) and audit custom/contrib modules for insecure unserialize() calls handling user input.

Recommended fix High confidence

10.5.9, 10.6.7, 11.2.11, or 11.3.7 (depending on your current major version branch)

  1. 1. Backup the entire Drupal site including database and files
  2. 2. Identify the current Drupal core version by checking the core/composer.json or running `drush status`
  3. 3. For Drupal 10.x versions < 10.5.9: upgrade to 10.5.9; for versions 10.6.0-10.6.6: upgrade to 10.6.7
  4. 4. For Drupal 11.x versions < 11.2.11: upgrade to 11.2.11; for versions 11.3.0-11.3.6: upgrade to 11.3.7
  5. 5. Run `composer update drupal/core --with-all-dependencies` to update Drupal core
  6. 6. Run `drush updatedb` or `php core/scripts/drupal.php updatedb` to execute database updates
  7. 7. Clear all Drupal caches using `drush cr` or the performance page
  8. 8. Verify the site functionality and that the update was successful
Caveat Minor version upgrades typically have no breaking changes; review Drupal release notes for any module/theme compatibility notes

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

Fix this in Drupal Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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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-2026-6366 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