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DrupalCMS

CVE-2026-55804

MEDIUM · 5.9 CVSS v3.1 Published 2026-07-10
Fix available
A fix is available. Upgrade to 10.5.12 / 10.6.11 or later.
See remediation →
65/100
Remediation priority · Elevated
Remotely reachable Zero-click 6 weeks old

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 versions: from 0.0.0 to 10.5.12, from 10.6.0 to 10.6.11, from 11.2.0 to 11.2.14, from 11.3.0 to 11.3.12, from 0.0.0 to 11.0.*, from 0.0.0 to 11.1.*.

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 an Object Injection vulnerability in Drupal core caused by improper handling of dynamically-determined object attributes. The vulnerability allows attackers to manipulate object properties through untrusted input, potentially leading to remote code execution depending on available gadget chains in the application.

MitigationUpgrade Drupal core to the latest patched version (10.5.13, 10.6.12, 11.2.15, or 11.3.13 or later). Review custom modules and themes for unsafe unserialize() calls that could be exploited in conjunction with this vulnerability.

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:< 10.5.12>= 10.6.0, < 10.6.11>= 11.0.0, < 11.2.14>= 11.3.0, < 11.3.12

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
None

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N

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
    Check the version file. For file-based checks: examine CHANGELOG.txt in the Drupal root directory for the version number at the top, or check composer.json for the 'drupal/core' version constraint. For command-line: run 'drush status' or 'composer show drupal/core' to retrieve the installed version.
    Affected if The installed version is less than 10.5.12, between 10.6.0-10.6.10, between 11.0.0-11.2.13, or between 11.3.0-11.3.11
  2. Compare version against affected ranges
    Using the version obtained from step 1, determine whether it falls within any of the following vulnerable ranges: < 10.5.12, >= 10.6.0 AND < 10.6.11, >= 11.0.0 AND < 11.2.14, or >= 11.3.0 AND < 11.3.12.
    Affected if The version falls into any of these ranges, indicating the core vulnerability is present
  3. Identify custom modules with unsafe PHP unserialization
    Search custom modules and themes in the /modules/custom and /themes/custom directories (or equivalent) for PHP code containing unserialize() calls on user-supplied or untrusted data. Use grep: 'grep -rn "unserialize" /path/to/modules/custom /path/to/themes/custom' and review each match for untrusted input sources such as $_GET, $_POST, $_REQUEST, or database values.
    Affected if Custom code contains unserialize() calls processing untrusted input, which could enable gadget chain exploitation if the core Object Injection is present

You are affected if your Drupal core version is within any of the vulnerable ranges listed and custom modules contain exploitable unserialize() gadget chains, or if untrusted input can reach dynamic object property manipulation in the core.

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 10.5.12 / 10.6.11 / 11.2.14 or later
Fixed in 10.5.1210.6.1111.2.14
Interim mitigation

Upgrade Drupal core to the latest patched version (10.5.13, 10.6.12, 11.2.15, or 11.3.13 or later). Review custom modules and themes for unsafe unserialize() calls that could be exploited in conjunction with this vulnerability.

Recommended fix High confidence

Drupal 10.5.12+ / 10.6.11+ / 11.2.14+ / 11.3.12+ depending on your branch

  1. 1. Identify your current Drupal core version by checking the CHANGELOG.txt file or running `drush status` or `composer show drupal/core`
  2. 2. Determine which version branch you are on (10.5.x, 10.6.x, 11.0.x/11.1.x, 11.2.x, or 11.3.x)
  3. 3. For Drupal 10.5.x: Upgrade to 10.5.12 or later
  4. 4. For Drupal 10.6.x: Upgrade to 10.6.11 or later
  5. 5. For Drupal 11.0.x or 11.1.x: Upgrade to 11.2.14 or later (these branches are EOL)
  6. 6. For Drupal 11.2.x: Upgrade to 11.2.14 or later
  7. 7. For Drupal 11.3.x: Upgrade to 11.3.12 or later
  8. 8. Run `composer update drupal/core --with-all-dependencies` to apply the upgrade
Caveat Major version upgrades (e.g., 10.x to 11.x) may require module/theme compatibility review and database migrations; test thoroughly in a staging environment

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

Fix this in Drupal Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,790
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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-2026-55804 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