CVE-2026-9726 Overview
CVE-2026-9726 is an object injection vulnerability in the Drupal AlternativeCommerce (Basket) contributed module. The flaw stems from improperly controlled modification of dynamically-determined object attributes [CWE-915]. Attackers can exploit this issue over the network without authentication or user interaction. The vulnerability affects Drupal AlternativeCommerce (Basket) versions from 0.0.0 through 2.1.17. Successful exploitation can lead to arbitrary object injection, potentially resulting in remote code execution, data tampering, or full site compromise.
Critical Impact
Unauthenticated attackers can inject arbitrary objects into vulnerable Drupal sites running AlternativeCommerce (Basket) up to version 2.1.17, enabling complete compromise of confidentiality, integrity, and availability.
Affected Products
- Drupal AlternativeCommerce (Basket) module — versions 0.0.0 through 2.1.17
- Drupal sites with the AlternativeCommerce (Basket) contributed module enabled
- All deployments processing user-controlled input through the affected module
Discovery Timeline
- 2026-07-10 - CVE-2026-9726 published to NVD
- 2026-07-14 - Last updated in NVD database
Technical Details for CVE-2026-9726
Vulnerability Analysis
CVE-2026-9726 is classified under [CWE-915]: Improperly Controlled Modification of Dynamically-Determined Object Attributes. The Drupal AlternativeCommerce (Basket) module fails to restrict which object attributes can be modified when processing attacker-controlled input. This condition enables object injection, where an attacker crafts input that instantiates or manipulates unintended objects during deserialization or dynamic assignment.
Because the attack vector is network-based and requires no privileges or user interaction, an attacker only needs reachability to the target Drupal site. Object injection in PHP-based platforms like Drupal commonly leads to remote code execution when combined with reachable gadget chains inside the Drupal core or contributed modules.
Root Cause
The root cause resides in code paths within AlternativeCommerce (Basket) that assign object properties or reconstruct objects from untrusted input without validating attribute names or class types. When object attributes are dynamically set from request data, an attacker can override sensitive properties or trigger unintended magic methods such as __wakeup, __destruct, or __toString during processing.
Attack Vector
An unauthenticated remote attacker submits a crafted HTTP request to a Drupal endpoint exposed by the AlternativeCommerce (Basket) module. The malicious payload manipulates object attribute assignment or deserialization logic to instantiate a controlled object graph. Refer to the Drupal Security Advisory for authoritative technical details.
No public proof-of-concept exploit code has been verified for this CVE. The vulnerability mechanism is described in prose because no verified exploitation code is available.
Detection Methods for CVE-2026-9726
Indicators of Compromise
- HTTP POST or GET requests to AlternativeCommerce (Basket) endpoints containing serialized PHP payloads (patterns beginning with O:, a:, or s:)
- Unexpected PHP process activity, outbound network connections, or file writes originating from the Drupal web server user
- Newly created administrative accounts, modified settings.php, or unauthorized changes to sites/default/files
Detection Strategies
- Inspect Drupal watchdog logs and web server access logs for anomalous requests targeting basket, cart, or checkout URLs from the module
- Deploy web application firewall rules that flag PHP serialization markers in query strings, POST bodies, and cookies
- Monitor for spawned child processes from php-fpm or apache2 that execute shells, curl, wget, or scripting interpreters
Monitoring Recommendations
- Enable verbose logging on the Drupal application and forward events to a centralized SIEM for correlation
- Baseline normal request patterns to AlternativeCommerce endpoints and alert on deviations in payload size or structure
- Track file integrity on the Drupal modules/contrib/alternativecommerce directory and PHP session storage
How to Mitigate CVE-2026-9726
Immediate Actions Required
- Update the Drupal AlternativeCommerce (Basket) module to a version later than 2.1.17 as soon as a fixed release is available
- Restrict access to basket and checkout endpoints via authentication or IP allowlisting until patching is complete
- Audit Drupal user accounts, session records, and file system changes for signs of prior exploitation
Patch Information
Refer to the Drupal Security Advisory SA-CONTRIB-2026-038 for the vendor-provided remediation guidance and fixed version details. Apply the referenced module update through the standard Drupal update workflow using composer update or the Drupal update manager.
Workarounds
- Disable and uninstall the AlternativeCommerce (Basket) module if the fixed version is not yet available or not required for site operation
- Deploy WAF signatures to block requests containing PHP serialized object markers directed at module endpoints
- Enforce least-privilege file system permissions on the Drupal web root to limit the impact of code execution
# Configuration example: disable the vulnerable module via Drush
drush pm:uninstall alternativecommerce_basket
drush cache:rebuild
# Verify module status
drush pm:list --status=enabled | grep -i alternativecommerce
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
