CVE-2026-53964
Description
Document Merge Service is a document template merge service providing an API to manage templates and merge them with given data. Prior to version 9.1.0, a remote code execution (RCE) via server-side template injection (SSTI) allows for user supplied code to be executed in the server's context where it is executed as the document-merge-server user with the UID 901 thus giving an attacker considerable control over the container. The vulnerability is limited to XLSX templates, were the xltpl library uses a npn-sandboxed Jinja environment for the processing of the template. This issue has been patched in version 9.1.0.
How to fix
- document-merge-service9.1.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| document-merge-servicePyPI | v < 9.1.0 | 9.1.0 |
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