# CVE-2026-44209: masci banks Remote Code Execution via SSTI in Prompt templates

Source: https://junglewise.ai/threats/cve-2026-44209-masci-banks-remote-code-execution-via-ssti-in-prompt-templates  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-26. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-44209 · Severity: high · CVSS 7.5 · Published 2026-05-26

The banks library, used for managing prompt templates in AI applications, is vulnerable to a flaw that allows attackers to execute arbitrary commands on the underlying server. If an application allows users to provide or customize their own templates, an attacker could gain full control over the system, steal sensitive data, or disrupt operations. This issue is resolved by upgrading to version 2.4.2.

Technologies: [Masci Banks](https://junglewise.ai/threats/technologies/banks). Vendors: [Masci](https://junglewise.ai/threats/vendors/masci).

## Quick answers

**Is CVE-2026-44209 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44209 being exploited in the wild.

**How severe is CVE-2026-44209?** High severity, with a CVSS score of 7.5, published 26 May 2026.

**Which products and versions are affected?** Masci Banks <= 2.4.1.

**Is there a fix for CVE-2026-44209?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-44209 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-44209?** Check whether you run Masci Banks at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The banks library (<= 2.4.1) initializes its Jinja2 environment using the standard `jinja2.Environment` instead of the `SandboxedEnvironment`. This lack of sandboxing allows an attacker to perform template injection if they can control the string passed to the `Prompt()` class. By using Jinja2 dunder attribute traversal (e.g., accessing `__globals__` or `__builtins__`), an attacker can escape the template context to execute arbitrary Python code or system commands via `os.popen`. The vulnerability is fixed in version 2.4.2 by migrating to `jinja2.sandbox.SandboxedEnvironment`.

## Affected products

- masci banks <= 2.4.1

## Identifiers

- CVE-2026-44209
- GHSA-gphh-9q3h-jgpp

## Timeline

- 2026-05-06: disclosed: Vulnerability published by masci/banks
- 2026-05-08: advisory: GitHub Advisory GHSA-gphh-9q3h-jgpp published
- 2026-05-26: other: NVD published CVE-2026-44209

## References

- [https://api.github.com/users/Anandakrishnasv](https://api.github.com/users/Anandakrishnasv)
- [https://github.com/Anandakrishnasv](https://github.com/Anandakrishnasv)
- [https://api.github.com/users/Anandakrishnasv/gists%7B/gist_id%7D](https://api.github.com/users/Anandakrishnasv/gists%7B/gist_id%7D)
- [https://api.github.com/users/Anandakrishnasv/repos](https://api.github.com/users/Anandakrishnasv/repos)
- [https://avatars.githubusercontent.com/u/279425301?v=4](https://avatars.githubusercontent.com/u/279425301?v=4)
- [https://api.github.com/users/Anandakrishnasv/events%7B/privacy%7D](https://api.github.com/users/Anandakrishnasv/events%7B/privacy%7D)

## Related threats

- [masci banks remote code execution via unsafe Tool import_path](https://junglewise.ai/threats/cve-2026-61536-masci-banks-remote-code-execution-via-unsafe-tool-import-path)
- [masci banks path traversal in media filters](https://junglewise.ai/threats/cve-2026-62663-masci-banks-path-traversal-in-media-filters)