CVE-2026-53405: Apache Syncope: Remote Code Execution via Flowable BPMN Groovy ScriptTask

[Francesco Chicchiriccò <ilgrosso () apache org>]

Severity: moderate 

Affected versions:

- Apache Syncope (org.apache.syncope.ext.flowable:syncope-ext-flowable-bpmn) 3.0.0-M0 through 3.0.16
- Apache Syncope (org.apache.syncope.ext.flowable:syncope-ext-flowable-bpmn) 4.0.0-M0 through 4.0.6
- Apache Syncope (org.apache.syncope.ext.flowable:syncope-ext-flowable-bpmn) 4.1.0-M0 through 4.1.1

Description:

Improper Isolation or Compartmentalization vulnerability in Apache Syncope.

An administrator with adequate entitlements can import arbitrary BPMN process definitions via the REST API and then 
start the process. When a BPMN process containing a Groovy scriptTask is imported and started, the Groovy script is 
executed directly on the server, with no sandbox.


This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 Through 4.0.6, from 4.1.0-M0 through 
4.1.1.




Users are recommended to upgrade to version 4.0.7 / 4.1.2, which fix this issue by wrapping Flowable's Groovy 
scriptTasks with security sandbox.

Credit:

follycat, Y0n3er (finder)

References:

https://syncope.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-53405