CVE-2026-62663
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk26th percentile - higher than 26% of all known CVEs
Summary
Banks generates meaningful LLM prompts using a simple template language. In versions prior to 2.4.4, all four media filters (image, audio, video, document) in banks accept untrusted user input as file paths via Path(value) and pass them directly to open(file_path, "rb") without any path sanitization, canonicalization, or directory restriction. An attacker who controls template variables passed to a banks Prompt can use path traversal (../) to read arbitrary files accessible to the Python process—including .env files, SSH keys, cloud credentials, source code, /etc/passwd, and /etc/shadow—with the content returned base64-encoded in the rendered prompt output, making exfiltration trivial.
Risk Assessment
The risk is the potential leakage of sensitive data such as credentials and keys, which could lead to further system compromise.
Recommendation
It is recommended to immediately update Banks to version 2.4.4 or later and validate all user input passed to templates.
Other vulnerabilities in Banks
See all- CVE-2026-71492Medium
In Banks before version 2.4.5, DirectoryPromptRegistry.set() in src/banks/registries/directory.py interpolates attacker-controlled Prompt.name and Prompt.version values into a Path without canonicalization or containment validation. Relative traversal such as ../victim/foo and an absolute Prompt.name can escape or discard the configured registry root, while overwrite=True permits replacement of existing target files. The poisoned name is persisted in index.json and reconstructed by _load(), allowing the out-of-root path to survive later registry loads. An application that forwards request data into these fields can therefore write Prompt.raw bytes to attacker-chosen paths writable by the application process. This issue is fixed in version 2.4.5.
- CVE-2026-61536High
Banks prior to version 2.4.3 contains a remote code execution vulnerability in {% completion %} blocks. An attacker can supply a malicious Tool JSON object with an import_path field that is resolved via importlib.import_module() and getattr() without any allowlist. When the LLM invokes a tool with a matching name, arbitrary Python code such as os.system or subprocess.getoutput can be executed.
- CVE-2026-44209High
Banks before version 2.4.2 uses unsandboxed jinja2.Environment() to render prompt templates, allowing Server-Side Template Injection (SSTI) leading to Remote Code Execution (RCE) on the host.
Original NVD description (English source)
Banks generates meaningful LLM prompts using a simple template language. In versions prior to 2.4.4, all four media filters (image, audio, video, document) in banks accept untrusted user input as file paths via Path(value) and pass them directly to open(file_path, "rb") without any path sanitization, canonicalization, or directory restriction. An attacker who controls template variables passed to a banks Prompt can use path traversal (../) to read arbitrary files accessible to the Python process—including .env files, SSH keys, cloud credentials, source code, /etc/passwd, and /etc/shadow—with the content returned base64-encoded in the rendered prompt output, making exfiltration trivial. This is particularly dangerous for applications that use banks to process user-provided template variables before sending prompts to an LLM. This issue has been fixed in version 2.4.4.