SA-CONTRIB-2026-274: Critical severity composer/drupal/single_content_sync vulnerability
Single Content Sync enables exporting and importing content, referenced entities, and files between Drupal sites. The module does not sufficiently validate file sources and destinations during content imports. An attacker can write arbitrary files, disclose sensitive local files accessible to the web server, or cause the server to make requests to internal or external resources. Depending on the server configuration, this may lead to remote code execution. Exploitation requires the import single content permission. This permission is marked as restricted starting with version 1.4.18. Remote code execution additionally depends on the server permitting execution of attacker-controlled files.
Credit
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
composer/drupal/single_content_syncto a version that resolves this vulnerability.Fixed in 1.4.19 - Configuration
Restrict the "import single content" permission; this permission is marked as restricted starting with version 1.4.18.
Single Content Sync import single content permission = restricted
Event History
Frequently Asked Questions
Who is able to exploit this issue?
Exploitation requires the import single content permission. That permission is marked as restricted starting with version 1.4.18.
What capabilities could an attacker gain through a successful exploit?
An attacker could write arbitrary files, disclose sensitive local files accessible to the web server, or induce requests to internal or external resources. Remote code execution is possible only if the server permits execution of attacker-controlled files.