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DrupalCMS

CVE-2023-5256

HIGH · 7.5 CVSS v3.1 Published 2023-09-28
Fix available
A fix is available. Upgrade to 9.5.11 / 10.0.11 or later.
See remediation →
81/100
Remediation priority · High
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
In certain scenarios, Drupal's JSON:API module will output error backtraces. With some configurations, this may cause sensitive information to be cached and made available to anonymous users, leading to privilege escalation. This vulnerability only affects sites with the JSON:API module enabled, and can be mitigated by uninstalling JSON:API. The core REST and contributed GraphQL modules are not affected.

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

The JSON:API module in Drupal outputs verbose error backtraces that, when cached under certain configurations, can expose sensitive system information to anonymous users. This information disclosure can enable privilege escalation attacks.

MitigationUninstall the JSON:API module if unused, or configure proper error handling and caching policies to prevent sensitive data from being cached and served to anonymous users.

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:>= 8.7.0, < 9.5.11>= 10.0.0, < 10.0.11>= 10.1.0, < 10.1.4

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

CVSS:3.1/AV:N/AC:H/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. Identify installed Drupal version
    Run `drush status` or check the `core/lib/Drupal.php` file for the VERSION constant, or look at `composer.json` for the drupal/core version
    Affected if The installed version falls outside the fixed ranges: not 9.5.11+, 10.0.11+, or 10.1.4+ (meaning it is within 8.7.0 to 9.5.10, 10.0.0 to 10.0.10, or 10.1.0 to 10.1.3)
  2. Verify JSON:API module is enabled
    Run `drush pm-list --type=module --status=enabled` and look for jsonapi module, or check the modules/jsonapi directory for existence and status in the database
    Affected if The JSON:API module is installed and enabled on the site
  3. Confirm anonymous users can access cached content
    Check the site configuration for caching settings that serve cached pages to anonymous users - examine settings.php for $settings['cache']['default'] and any JSON:API specific cache configuration, or test by making an authenticated request then an anonymous request to a JSON:API endpoint
    Affected if Page caching is enabled for anonymous users and JSON:API endpoints are publicly accessible without authentication
  4. Inspect error handling configuration
    Check settings.php for $config['system.logging'] or $config['system.site'] error_level setting, and look for any custom error handlers that may expose backtraces
    Affected if Error display is set to verbose mode or backtraces are being included in JSON:API error responses

A site is affected if it runs a vulnerable Drupal version (8.7.0-9.5.10, 10.0.0-10.0.10, or 10.1.0-10.1.3) with the JSON:API module enabled, has page caching for anonymous users, and verbose error handling that can expose backtraces in cached responses.

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 9.5.11 / 10.0.11 / 10.1.4 or later
Fixed in 9.5.1110.0.1110.1.4
Interim mitigation

Uninstall the JSON:API module if unused, or configure proper error handling and caching policies to prevent sensitive data from being cached and served to anonymous users.

Recommended fix High confidence

Drupal 9.5.11, 10.0.11, or 10.1.4 (choose based on current branch)

  1. Identify the current Drupal version branch (9.x, 10.0.x, or 10.1.x) by running 'drush status' or checking the composer.json
  2. Back up the Drupal database and all files before proceeding
  3. Plan the upgrade: for Drupal 9.x upgrade to 9.5.11; for Drupal 10.0.x upgrade to 10.0.11; for Drupal 10.1.x upgrade to 10.1.4
  4. Test the upgrade in a staging environment first
  5. Run 'composer require drupal/core:^9.5.11 --no-update' (or appropriate version for your branch) in the project root
  6. Run 'composer update drupal/core --with-all-dependencies' to update Drupal core
  7. Clear Composer autoload: 'composer dump-autoload'
  8. Run database updates: 'drush updb' or 'php core/scripts/drupal update-db'
Caveat Minor version upgrades in Drupal typically have few breaking changes, but review the release notes for your target version for any module or configuration considerations

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

Fix this in Drupal Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

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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-2023-5256 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