CVE-2026-15083: Drupal ECA Module RCE Vulnerability

CVE-2026-15083 Overview

CVE-2026-15083 is an object injection vulnerability in the Drupal ECA (Event - Condition - Action) contributed module. The flaw is classified under [CWE-915] Improperly Controlled Modification of Dynamically-Determined Object Attributes. Attackers with low privileges can manipulate object attributes during deserialization, leading to unauthorized modification of application state. The vulnerability affects ECA versions from 0.0.0 to 2.1.20, 3.0.0 to 3.0.12, and 3.1.0 to 3.1.4. Successful exploitation requires network access and high attack complexity but no user interaction.

Critical Impact
Authenticated attackers can inject crafted objects to modify dynamically-determined attributes, resulting in limited confidentiality and integrity impact on affected Drupal sites.

Affected Products

Drupal ECA: Event - Condition - Action versions 0.0.0 through 2.1.20
Drupal ECA: Event - Condition - Action versions 3.0.0 through 3.0.12
Drupal ECA: Event - Condition - Action versions 3.1.0 through 3.1.4

Discovery Timeline

2026-07-10 - CVE-2026-15083 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2026-15083

Vulnerability Analysis

The ECA (Event - Condition - Action) module extends Drupal with a no-code workflow engine for building automated processes. The vulnerability resides in code paths where object attributes are set based on user-controllable input without adequate validation of the target attribute or its type. This class of flaw, tracked as [CWE-915], enables attackers to influence internal object state that developers assumed to be trusted.

Exploitation requires an authenticated account with sufficient privileges to interact with ECA workflow processing. The high attack complexity indicates that specific conditions must be met to reach the vulnerable code path. Impact is limited to partial confidentiality and integrity loss, with no availability impact.

Root Cause

The underlying weakness stems from the module trusting attribute names or values supplied during dynamic object manipulation. When PHP dynamically assigns properties to objects based on external input, an attacker can overwrite properties that control security-sensitive behavior. This is the canonical pattern for PHP object injection, where the application resolves object attributes at runtime without an allowlist.

Attack Vector

The attack is delivered over the network against a vulnerable Drupal site running the ECA module. An authenticated attacker submits crafted input that reaches the object attribute assignment routine within ECA. The manipulated object attributes then influence downstream logic, allowing the attacker to read or modify data outside their intended scope. Refer to the Drupal Security Advisory for technical specifics on the affected code paths.

Detection Methods for CVE-2026-15083

Indicators of Compromise

Unexpected modifications to ECA workflow configurations or entity properties that do not correspond to legitimate administrative activity.
Web server logs showing authenticated POST requests to ECA endpoints containing serialized payloads or unusual attribute names.
Drupal watchdog entries referencing PHP notices about undefined properties or type mismatches originating from ECA modules.

Detection Strategies

Audit installed Drupal contributed modules and compare the ECA version against the vulnerable ranges listed in the advisory.
Enable verbose logging on Drupal form submissions and inspect requests targeting ECA workflow processing for anomalous parameter structures.
Correlate authenticated session activity with configuration change events to identify low-privilege users triggering high-impact object modifications.

Monitoring Recommendations

Forward Drupal application logs and web server access logs to a centralized analytics platform for correlation and retention.
Monitor for privilege escalation patterns following ECA interactions, including new administrator role assignments or permission changes.
Alert on outbound network connections from the Drupal host that follow ECA-related requests, which may indicate follow-on exploitation.

How to Mitigate CVE-2026-15083

Immediate Actions Required

Identify all Drupal installations running the ECA module and inventory the installed version using drush pm:list or the module administration page.
Upgrade ECA to version 2.1.21, 3.0.13, or 3.1.5 or later as indicated in the Drupal Security Advisory.
Review recent ECA workflow configurations and audit logs for signs of tampering by low-privilege accounts.

Patch Information

The Drupal security team addressed CVE-2026-15083 in fixed releases of the ECA module. Site administrators should consult the Drupal Security Advisory SA-CONTRIB-2026-074 for the specific patched versions and apply the update through Composer or the Drupal update manager.

Workarounds

Restrict permissions to ECA workflow configuration so that only trusted administrative roles can create or edit models.
Place the Drupal administrative interface behind network-level access controls such as VPN or IP allowlisting until the module is upgraded.
Temporarily disable the ECA module on sites that cannot be immediately updated if workflow automation is not business-critical.

bash

# Update ECA module via Composer to a patched release
composer update drupal/eca --with-dependencies
drush updatedb
drush cache:rebuild