--- title: "CVE-2026-53964: Document Merge Service - Remote Code Execution" description: "Document Merge Service < 9.1.0 contains a server-side template injection caused by unsafe processing of XLSX templates using npn-sandboxed Jinja environment, letting remote attackers execute code as document-merge-server user, exploit requires crafted XLSX template." url: https://panop.io/threat-heartbeat/CVE-2026-53964/ --- # CVE-2026-53964 Document Merge Service - Remote Code Execution Document Merge Service < 9.1.0 contains a server-side template injection caused by unsafe processing of XLSX templates using npn-sandboxed Jinja environment, letting remote attackers execute code as document-merge-server user, exploit requires crafted XLSX template. CVSS base score 7.2 /10 High CISA KEV Not listed Public exploit None known Authentication Required EPSS 0.49% chance of exploitation in 30 days [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-53964) ## Details Type Remote Code Execution Impact Remote Code Execution CVSS vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Published 1 October 2026 Updated 15 October 2026 Weakness [CWE-1336](https://cwe.mitre.org/data/definitions/1336.html) ## Vendor fix Upgrade to version 9.1.0 or later. Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them. ## References - [https://nvd.nist.gov/vuln/detail/CVE-2026-53964](https://nvd.nist.gov/vuln/detail/CVE-2026-53964) - [https://github.com/adfinis/document-merge-service/releases/tag/v9.1.0](https://github.com/adfinis/document-merge-service/releases/tag/v9.1.0) - [https://github.com/adfinis/document-merge-service/security/advisories/GHSA-w47q-945m-q9pc](https://github.com/adfinis/document-merge-service/security/advisories/GHSA-w47q-945m-q9pc) [← All CVEs](https://panop.io/threat-heartbeat/) ## What this record can't tell you - Whether you run the affected software, and where - Whether an attacker can actually reach and exploit it - The misconfigurations that never get a CVE number - What it would cost the business, ranked into what to fix first Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)