adfinis/document-merge-service · Security
Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)
- GHSA ID
- GHSA-w47q-945m-q9pc
- CVE ID
- CVE-2026-53964
- Severity
- high
- Published
- Updated
- CVSS
- 7.2 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- CVSS v3
- 7.2 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Description
Impact
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.
Patches
It has been patched in v9.1.0
Workarounds
Disable the upload/usage of XLSX templates.
References
Are there any links users can visit to find out more?
https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection/jinja2-ssti
CWEs
- CWE-1336 · Improper Neutralization of Special Elements Used in a Template Engine