{"id":"CVE-2026-33140","aliases":["PYSEC-2026-3029"],"url":"https://o3.security/vulnerability/CVE-2026-33140","summary":"Stored XSS in PySpector HTML Report Generation leads to Javascript Code Execution","details":"### Summary\nPySpector 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.\n\n### Impact\nAn 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:\n- Arbitrary DOM manipulation\n- Redirects to attacker-controlled pages\n- Theft of locally accessible data via `fetch()` or `XMLHttpRequest` to `file://` paths (browser-dependent)\n\nAny user of PySpector who scans untrusted code and generates HTML reports, is potentially affected.\n\n### PoC\n\nThe following steps reproduce the vulnerability on PySpector `<= 0.1.6`:\n1. 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:\n<img width=\"871\" height=\"752\" alt=\"image\" src=\"https://github.com/user-attachments/assets/1b0a57f2-3632-4347-a9b7-6a94dc2e82b2\" />\n2. Open the generated HTML report in any browser:\n<img width=\"1920\" height=\"920\" alt=\"image\" src=\"https://github.com/user-attachments/assets/a4075c4a-6153-41b4-ad77-81d009d7a9f8\" />","published":"2026-03-18T16:33:46Z","modified":"2026-07-13T16:43:19.639829472Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pyspector","fixedVersion":"0.1.7"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/ParzivalHack/PySpector/security/advisories/GHSA-2gmv-2r3v-jxj2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33140"},{"type":"PACKAGE","url":"https://github.com/ParzivalHack/PySpector"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-13T16:43:19.639829472Z"}}