Description
An SSTI (Server-Side Template Injection) vulnerability exists in the get_dunning_letter_text method of Frappe ERPNext through 15.89.0. The function renders attacker-controlled Jinja2 templates (body_text) using frappe.render_template() with a user-supplied context (doc). Although Frappe uses a custom SandboxedEnvironment, several dangerous globals such as frappe.db.sql are still available in the execution context via get_safe_globals(). An authenticated attacker with access to configure Dunning Type and its child table Dunning Letter Text can inject arbitrary Jinja expressions, resulting in server-side code execution within a restricted but still unsafe context. This can leak database information.
Affected products
frappe: erpnext
References2
- iamanc.github.io/post/erpnext-ssti-bug-1 ExploitThird Party Advisory
- www.notion.so/SSTI-bug-1-239e6086eadc8096bfcfe90551a3a483?sourc… ExploitThird Party Advisory
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 49 · as of 11 November 2026
- CWE
- CWE-94CWE-1336
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.