CVE-2026-53964
### 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](https://github.com/adfinis/document-merge-service/releases/tag/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
Properties
- ghsa_id
- GHSA-w47q-945m-q9pc
- summary
- Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)
- severity
- high
- cvss_score
- 7.2
- cve_id
- CVE-2026-53964
- cvss_vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- is_ghsa_only
- false
- ghsa_published
- 2026-08-19T19:17:19Z
- source_url
- https://github.com/advisories/GHSA-w47q-945m-q9pc
- ghsa_updated
- 2026-08-19T19:17:20Z
Related Entities (4)
REPORTED_BY (1)
VULNERABLE_TO (1)
AFFECTS (1)
HAS_WEAKNESS (1)
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