Hyland Alfresco Transformation Service Argument Injection RCE

The impact of CVE-2026-26339 is severe. Successful exploitation allows an attacker to gain complete control over the affected Alfresco Transformation Service instance. This could lead to data breaches, system compromise, and potential lateral movement within the network. An unauthenticated attacker can trigger this vulnerability, meaning no prior authentication is required, significantly broadening the attack surface. The ability to execute arbitrary code opens the door to a wide range of malicious activities, including installing malware, modifying system configurations, and stealing sensitive data. This vulnerability shares similarities with other argument injection flaws where improper input validation allows attackers to manipulate program behavior.

Organizations utilizing Alfresco Transformation Service in production environments, particularly those with exposed document processing endpoints, are at significant risk. Environments with weak access controls or inadequate input validation are especially vulnerable. Shared hosting environments where multiple users share the same Alfresco instance are also at increased risk.

• java / server:

ps -ef | grep TransformationService

• java / server:

journalctl -u TransformationService | grep -i "argument injection"

• generic web:

curl -I <alfresco_transformation_service_url>/processDocument

• generic web:

 grep -i "argument injection" /var/log/apache2/access.log

1. 2026-02-19Disclosure

   disclosure

1. Reserviert2026-02-13
2. Veröffentlicht2026-02-19
3. Geändert2026-02-20
4. EPSS aktualisiert2026-03-23

The primary mitigation for CVE-2026-26339 is to upgrade to version 5.2.4 of the Alfresco Transformation Service. If an immediate upgrade is not feasible, consider implementing temporary workarounds. Restrict access to the document processing functionality to trusted users and networks. Implement strict input validation on all user-supplied data to prevent argument injection. Monitor system logs for suspicious activity related to document processing. While a WAF or proxy may offer some protection, it is unlikely to be sufficient on its own given the nature of the vulnerability. After upgrading, confirm the fix by attempting to trigger the document processing functionality with malicious input and verifying that the system behaves as expected.