CVE-2026-81269: Drupal Data Field Auth Bypass Vulnerability

CVE-2026-81269 Overview

CVE-2026-81269 is a Missing Authorization vulnerability [CWE-862] in the Drupal Data field contributed module. The flaw allows unauthenticated attackers to perform forceful browsing against protected resources exposed by the module. Affected versions include Data field releases from 0.0.0 through 2.0.13. The issue is network-accessible with low attack complexity and requires no user interaction. Successful exploitation results in limited disclosure of information that should require authorization to view.

Critical Impact
Unauthenticated attackers can access resources exposed by the Drupal Data field module without proper authorization checks, leading to confidentiality impact on affected Drupal sites.

Affected Products

Drupal Data field module versions 0.0.0 through 2.0.13
Drupal sites using the Data field contributed module
Any Drupal deployment referencing advisories SA-2026-108 and SA-2026-111

Discovery Timeline

2026-09-02 - CVE-2026-81269 published to NVD
2026-09-02 - Last updated in NVD database

Technical Details for CVE-2026-81269

Vulnerability Analysis

The Data field module fails to enforce authorization checks on one or more code paths that expose field data. Because access control is missing rather than misconfigured, attackers do not need valid credentials or elevated privileges to reach the affected endpoints. The result is a forceful browsing condition where a remote user can request URLs or resources directly and receive content that should have been gated behind an access check.

Forceful browsing exploits the assumption that resources are protected simply because they are not linked in the user interface. When the module does not verify the caller's permissions, obscurity becomes the only control. The impact is limited to confidentiality, with no integrity or availability effect according to the CVSS vector.

Root Cause

The root cause is a missing authorization check in the Data field module's request handling logic. Drupal expects contributed modules to invoke access callbacks or apply route-level permission requirements before returning data. The affected code paths in versions up to 2.0.13 omit these checks, so the module returns data based on the request alone.

Attack Vector

An attacker sends crafted HTTP requests to endpoints exposed by the Data field module on a target Drupal site. No authentication, session, or user interaction is required. The attacker enumerates or guesses resource identifiers and retrieves content that the site owner intended to restrict. Refer to the Drupal Security Advisory SA-2026-108 and Drupal Security Advisory SA-2026-111 for advisory-specific technical details.

No verified public exploit code is available at the time of publication.

Detection Methods for CVE-2026-81269

Indicators of Compromise

Unauthenticated HTTP requests to Data field module routes returning 200 OK responses with field content
Sequential or enumeration-style access patterns from a single source IP targeting Data field endpoints
Access log entries showing anonymous users retrieving resources normally restricted to authenticated roles

Detection Strategies

Review Drupal access logs and web server logs for requests to Data field module paths from anonymous sessions
Correlate anonymous request volume against Data field endpoints and alert on statistical anomalies
Compare responses served to anonymous users against the site's documented public content inventory

Monitoring Recommendations

Enable verbose access logging on the Drupal application and forward logs to a centralized analytics platform
Monitor for scanner user-agents and rapid enumeration patterns against node, entity, and Data field routes
Track outbound response sizes on anonymous requests to identify unexpected data disclosure

How to Mitigate CVE-2026-81269

Immediate Actions Required

Update the Drupal Data field module to a version later than 2.0.13 as directed by the Drupal security team
Audit site permissions and confirm that anonymous and authenticated roles do not have unintended access to Data field content
Review recent access logs for evidence of exploitation prior to patching

Patch Information

Drupal has published guidance in Drupal Security Advisory SA-2026-108 and Drupal Security Advisory SA-2026-111. Administrators should follow the fixed-version guidance in these advisories and apply the update using standard Drupal module update procedures.

Workarounds

Restrict access to Data field module endpoints at the web server or reverse proxy layer until the module is updated
Temporarily disable the Data field module on sites where it is not actively required
Apply a web application firewall rule to block anonymous requests to known Data field routes

bash

# Example: update Drupal contributed modules using Composer
composer update drupal/data --with-dependencies
drush updatedb
drush cache:rebuild