CVE-2026-53964 Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)

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 i...

CVE-2026-53964

The Document Merge Service is vulnerable to Remote Code Execution (RCE) via Server-Side Template Injection (SSTI) in versions prior to 9.1.0 . The flaw exists because the xltpl library uses a non-sandboxed Jinja environment to process XLSX templates . An attacker can supply malicious template con...