CVE-2026-53964

Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)

Published Oct 1, 2026 CVSS 3.1 · 7.2 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-w47q-945m-q9pc Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)
History
Type Values Removed Values Added
First Time appeared Adfinis
Adfinis document Merge Service
Vendors & Products Adfinis
Adfinis document Merge Service
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)
Weaknesses CWE-1336
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 1, 2026, 8:13 PM
Reserved
Jun 11, 2026, 3:50 PM
Status
Deferred
Published
Oct 1, 2026, 8:17 PM
Modified
Oct 2, 2026, 6:47 PM