How severe is CVE-2026-33140?

No CVSS score has been assigned to CVE-2026-33140 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-33140?

CVE-2026-33140 affects the following packages: pyspector (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2026-33140?

Update pyspector to 0.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33140 is resolved across your whole dependency graph.

How do I detect CVE-2026-33140 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyspector, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-33140 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-33140 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-33140 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-33140?

CVE-2026-33140 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 13th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-33140?

CVE-2026-33140 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-33140 published, and has it been updated?

CVE-2026-33140 was published on March 18, 2026 and was last updated on July 13, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

CVE-2026-33140 — pyspector

CVE-2026-33140 is a Cross-site Scripting (XSS) vulnerability in pyspector. A fix is available for pyspector — see the affected versions and patch details below.

Stored XSS in PySpector HTML Report Generation leads to Javascript Code Execution

Also known asPYSEC-2026-3029

Published

Mar 18, 2026

Updated

Jul 13, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33140.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk-0.04%

Lower risk than most CVEs13th percentile — riskier than 13% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐍pyspector

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Summary

PySpector versions <= 0.1.6 are affected by a stored Cross-Site Scripting (XSS) vulnerability in the HTML report generator. When PySpector scans a Python file containing JavaScript payloads (i.e. inside a string passed to eval() ), the flagged code snippet is interpolated into the HTML report without sanitization. Opening the generated report in a browser causes the embedded JavaScript to execute in the browser's local file context.

Impact

An attacker can craft a malicious Python file (for example, hosted in a public repository), designed to be scanned by PySpector. When a victim scans this file and opens the resulting HTML report, arbitrary JavaScript executes in their browser. While the file:// context limits the attacker's ability to exfiltrate cookies or make credentialed requests, the following is still achievable:

Arbitrary DOM manipulation
Redirects to attacker-controlled pages
Theft of locally accessible data via fetch() or XMLHttpRequest to file:// paths (browser-dependent)

Any user of PySpector who scans untrusted code and generates HTML reports, is potentially affected.

PoC

The following steps reproduce the vulnerability on PySpector <= 0.1.6:

Create a malicious Python file containing a JavaScript payload embedded in a string argument to eval(), and run PySpector against the file, generating an HTML report: <img width="871" height="752" alt="image" src="https://github.com/user-attachments/assets/1b0a57f2-3632-4347-a9b7-6a94dc2e82b2" />
Open the generated HTML report in any browser:

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`pyspector`	all versions	0.1.7`pip install --upgrade 'pyspector==0.1.7'`

Affected Products

1 product · 1 configurations

Application

pyspectorparzivalhack

< 0.1.7

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyspector, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pyspector to 0.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33140 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Summary PySpector versions `<= 0.1.6` are affected by a stored Cross-Site Scripting (XSS) vulnerability in the HTML report generator. When PySpector scans a Python file containing JavaScript payloads (i.e. inside a string passed to `eval()` ), the flagged code snippet is interpolated into the HTML report without sanitization. Opening the generated report in a browser causes the embedded JavaScript to execute in the browser's local file context. ### Impact An attacker can craft a malicious Python file (for example, hosted in a public repository), designed to be scanned by PySpector. When a