# CVE-2026-33140: PYSEC-2026-3029 - Stored XSS in PySpector HTML Report Generation leads to Javascript Code Execution

Source: https://junglewise.ai/threats/cve-2026-33140-pyspector-stored-xss-in-html-report-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-13. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-33140 · Severity: medium · CVSS 4 · Published 2026-07-13

PySpector is a Python code analysis tool that generates HTML reports highlighting code quality issues. A stored cross-site scripting vulnerability in the HTML report generator allows malicious JavaScript embedded in scanned Python files to execute in a user's browser when they open the generated report. An attacker could craft a malicious Python file, trick a user into scanning it, and then execute arbitrary JavaScript in their browser to manipulate content, redirect to phishing sites, or steal local files.

Technologies: [pyspector (PyPI)](https://junglewise.ai/threats/technologies/pyspector). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-33140 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33140 being exploited in the wild.

**How severe is CVE-2026-33140?** Medium severity, with a CVSS score of 4, published 13 July 2026.

**Which products and versions are affected?** pyspector (PyPI) ECOSYSTEM:introduced=0,fixed=0.1.7.

**Is there a fix for CVE-2026-33140?** Yes. pyspector (PyPI): upgrade to 0.1.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-33140 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-33140?** Check whether you run pyspector (PyPI) 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.

## How to fix

- pyspector (PyPI): upgrade to 0.1.7 or later

  ```sh
  pip install "pyspector>=0.1.7"
  ```


## Technical details

PySpector versions ≤0.1.6 contain a stored XSS vulnerability (CWE-79) in the HTML report generator. When scanning a Python file containing JavaScript payloads (e.g., within string arguments to eval()), the flagged code snippet is interpolated into the generated HTML report without sanitization. The attack requires a user to scan an attacker-controlled Python file and open the resulting HTML report in a browser. While the file:// origin context limits exfiltration of credentials, an attacker can still achieve DOM manipulation, redirect attacks, and potential theft of locally accessible data via file:// fetch requests. The vulnerability has been patched in version 0.1.7.

## Affected products

- PySpector PySpector ≤0.1.6

## Identifiers

- CVE-2026-33140
- GHSA-2gmv-2r3v-jxj2
- PYSEC-2026-3029

## Timeline

- 2026-03-18: disclosed
- 2026-03-18: patched: Fixed in version 0.1.7

## References

- [https://github.com/ParzivalHack/PySpector/security/advisories/GHSA-2gmv-2r3v-jxj2](https://github.com/ParzivalHack/PySpector/security/advisories/GHSA-2gmv-2r3v-jxj2)

## Related threats

- [PYSEC-2026-3030 - PySpector has a Plugin Sandbox Bypass leads to Arbitrary Code Execution](https://junglewise.ai/threats/cve-2026-33139-pyspector-has-a-plugin-sandbox-bypass-leads-to-arbitrary-code)
- [PySpector has a Plugin Code Execution Bypass via Incomplete Static Analysis in PluginSecurity.validate_plugin_code](https://junglewise.ai/threats/cve-2026-41206-pyspector-has-a-plugin-code-execution-bypass-via-incomplete)