Threats affecting pkg:github/adfinis/document-merge-service

CVE-2026-53964 is a high-severity vulnerability in adfinis document-merge-service prior to version 9.1.0. It allows remote code execution via server-side template injection in XLSX templates processed by the xltpl library using a non-sandboxed Jinja environment. The flaw enables execution of user-supplied code with the privileges of the document-merge-server user, potentially compromising the container. This issue has been fixed in version 9.1.0.

Document Merge Service is a document template merge service providing an API to manage templates and merge them with given data. Versions 6.5.1 and prior are vulnerable to remote code execution via server-side template injection which, when executed as root, can result in full takeover of the affected system. As of time of publication, no patched version exists, nor have any known workarounds been disclosed.