CVE-2026-53964
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.
- CVSS 3.1
- 7.2
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-25)
- CWE
- CWE-1336
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w47q-945m-q9pc | PyPI | document-merge-service | <9.1.0 | 9.1.0 |
| PYSEC-2026-3830 | PyPI | document-merge-service | <9.1.0 | 9.1.0 |