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Fencer Intel
high 8.8

CVE-2025-66434 json

An SSTI (Server-Side Template Injection) vulnerability exists in the get_dunning_letter_text method of Frappe ERPNext through 15.89.0.

published 10mo ago modified 6d ago also EUVD-2025-203397

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

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.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
10mo ago

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • notion.so https://www.notion.so/SSTI-bug-1-239e6086eadc8096bfcfe90551a3a483?source=copy_link referenced PoC, tagged "exploit" by a source, unverified
  • iamanc.github.io https://iamanc.github.io/post/erpnext-ssti-bug-1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness
  • CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine
  • CWE-94 Improper Control of Generation of Code

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.