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DrupalCMS

CVE-2026-55803

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

Object Injection vulnerability in Drupal core caused by improperly controlled modification of dynamically-determined object attributes. Attackers can manipulate object properties through untrusted input, potentially leading to code execution or other malicious outcomes.

MitigationUpdate Drupal core to the latest patched version (10.5.13+, 10.6.12+, 11.2.15+, 11.3.13+, or 11.4.0+) as specified in the official Drupal security advisory.

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. Check installed Drupal core version via Drush
    Run `drush status` or `drush core:status` and look for the 'Drupal version' field
    Affected if The reported version is < 10.5.12, between 10.6.0-10.6.11, between 11.0.0-11.2.14, or between 11.3.0-11.3.12
  2. Check Drupal core version from composer.json
    Open the composer.json file in the Drupal root directory and locate the `drupal/core` entry under `require`. The version specified there is the installed version
    Affected if The drupal/core version is < 10.5.12, between 10.6.0-10.6.11, between 11.0.0-11.2.14, or between 11.3.0-11.3.12
  3. Check Drupal version from core/lib/Drupal.php
    Open the file `web/core/lib/Drupal.php` (or `sites/all/modules` path depending on install) and locate the `VERSION` constant
    Affected if The VERSION constant value is < 10.5.12, between 10.6.0-10.6.11, between 11.0.0-11.2.14, or between 11.3.0-11.3.12
  4. Check Drupal version via administrative UI
    Log in as an administrator and navigate to the Status Report at /admin/reports/status. The Drupal core version is displayed on that page
    Affected if The version shown in the Status Report is < 10.5.12, between 10.6.0-10.6.11, between 11.0.0-11.2.14, or between 11.3.0-11.3.12

You are affected if your Drupal core version falls within any of the vulnerable ranges: < 10.5.12, 10.6.0-10.6.11, 11.0.0-11.2.14, or 11.3.0-11.3.12.

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

Update Drupal core to the latest patched version (10.5.13+, 10.6.12+, 11.2.15+, 11.3.13+, or 11.4.0+) as specified in the official Drupal security advisory.

Recommended fix High confidence

Upgrade to Drupal 10.5.12, 10.6.11, 11.2.14, or 11.3.12 (depending on your current branch)

  1. 1. Determine your current Drupal core version by checking the CHANGELOG.txt file or running `drush status` or `composer show drupal/core`
  2. 2. Identify which version branch you are currently 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 version 10.5.12 or later
  4. 4. For Drupal 10.6.x: Upgrade to version 10.6.11 or later
  5. 5. For Drupal 11.0.x: Upgrade to version 11.2.14 or later (11.0.x and 11.1.x are not separately patched, jump to 11.2.14)
  6. 6. For Drupal 11.1.x: Upgrade to version 11.2.14 or later
  7. 7. For Drupal 11.2.x: Upgrade to version 11.2.14 or later
  8. 8. For Drupal 11.3.x: Upgrade to version 11.3.12 or later
Caveat Review the release notes for your target version to check for any breaking changes or deprecated features; jumping multiple minor versions (e.g., 11.0.x to 11.2.14) may require additional testing

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

Fix this in Drupal Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing8.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,800
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,080.

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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-2026-55803 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