THREATOPS

THREAT OPS › Threat News › [GHSA] GHSA-w47q-945m-q9pc (high) — Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)

[GHSA] GHSA-w47q-945m-q9pc (high) — Document Merge Service vulnerable to RCE via SSTI (xlsx tempaltes)

highgithub_advisoriesPublished 2026-08-19

GHSA-w47q-945m-q9pc Severity: high CVE: CVE-2026-53964

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

### 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 th

MITRE ATT&CK techniques

Template InjectionT1221

Indicators of compromise

CVE-2026-53964cve
https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection/jinja2-sstiurl

Original source: https://github.com/advisories/GHSA-w47q-945m-q9pc