PT-2026-66542 · Masci · Banks

CVE-2026-61536

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Published

2026-07-30

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Updated

2026-07-30

CVSS v3.1

7.5

High

VectorAV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Banks generates meaningful LLM prompts using a simple template language. In versions prior to 2.4.3, banks parses Tool JSON objects from the rendered body of {% completion %} blocks and later resolves their import path field through importlib.import module(...) + getattr(...) to obtain the callable that handles a tool call. There is no allowlist or sanitization on import path, so any importable Python attribute (e.g. os.system, subprocess.getoutput) can be selected. When the LLM emits a tool calls entry whose function.name matches the attacker-supplied tool name, the resolved callable is invoked with kwargs decoded from tool call.function.arguments, yielding arbitrary code execution in the banks-hosting process. This is distinct from GHSA-gphh-9q3h-jgpp / CVE-2026-44209. That advisory was fixed in 2.4.2 by switching src/banks/env.py from Environment to SandboxedEnvironment. The fix does not touch src/banks/extensions/completion.py, and the unsafe import + getattr chain still executes on 2.4.2. The malicious Tool JSON is plain text in the rendered template body — it requires no Jinja attribute access, so the sandbox is irrelevant. This issue has been fixed in version 2.4.3.

Fix

Code Injection

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Weakness Enumeration

Related Identifiers

CVE-2026-61536

Affected Products

Banks