Vulnerability · Published Aug 20, 2026 · Assigned by GitHub_M
CVE-2026-71492Banks: Path traversal in `DirectoryPromptRegistry.set()` allows arbitrary file write outside the registry root
Medium 6.0
In plain English
A medium-severity path traversal in banks from masci. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Banks generates meaningful LLM prompts using a simple template language. Prior to 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | banks | 2.4.5 | GHSA-x8wg-4xgc-vr54 |
| PyPI | banks | 2.4.5 | PYSEC-2026-3810 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/masci/banks/security/advisories/GHSA-x8wg-4xgc-vr54 x_refsource_CONFIRM
- https://github.com/masci/banks/pull/77 x_refsource_MISC
- https://github.com/masci/banks/commit/a215f6d779966945c56e0af5abed1ae5916fd9d3 x_refsource_MISC
- https://github.com/masci/banks/releases/tag/v2.4.5 x_refsource_MISC