CVE-2026-88746: idccms V1.70 XSS Vulnerability

CVE-2026-88746 Overview

CVE-2026-88746 is a Cross-Site Scripting (XSS) vulnerability in idccms V1.70. The flaw resides in the /admin/makeDiy_deal.php endpoint, which fails to properly sanitize user-controlled input before rendering it in the response. An attacker can inject arbitrary JavaScript that executes in the browser of any administrator who interacts with a crafted request. The vulnerability is classified under [CWE-79] (Improper Neutralization of Input During Web Page Generation).

Critical Impact
Successful exploitation allows attackers to hijack administrator sessions, steal authentication tokens, or perform actions in the administrative context of idccms V1.70.

Affected Products

idccms V1.70
Administrative component: /admin/makeDiy_deal.php
Web-facing deployments of the affected version

Discovery Timeline

2026-09-21 - CVE-2026-88746 published to the National Vulnerability Database
2026-09-22 - Last updated in NVD database

Technical Details for CVE-2026-88746

Vulnerability Analysis

The vulnerability affects idccms V1.70, a content management system used for internet data center websites. The administrative script /admin/makeDiy_deal.php processes user-supplied parameters without applying output encoding or input sanitization. When an authenticated administrator triggers a request containing attacker-controlled content, the server reflects the payload into the HTML response. The browser then executes the injected script in the trusted origin of the application.

The attack scope is marked as changed, meaning the injected script can affect resources beyond the vulnerable component itself. User interaction is required, which typically involves an administrator clicking a crafted link or visiting a page controlled by the attacker.

Root Cause

The root cause is missing output encoding in /admin/makeDiy_deal.php. The script writes request parameters directly into the HTML response without converting characters such as <, >, ", and ' into their HTML entity equivalents. This allows <script> tags and event handlers to be rendered as active markup rather than inert text.

Attack Vector

An attacker crafts a URL or form submission containing a JavaScript payload targeting a parameter processed by makeDiy_deal.php. The attacker delivers this link to an authenticated administrator through phishing, a forum post, or a compromised site. When the administrator loads the URL, the payload executes with the administrator's session privileges. See the GitHub XSS Vulnerability Report for a proof-of-concept demonstration.

No verified exploit code is reproduced here. Refer to the linked report for technical payload details.

Detection Methods for CVE-2026-88746

Indicators of Compromise

HTTP requests to /admin/makeDiy_deal.php containing <script>, onerror=, onload=, or javascript: substrings in parameters
URL-encoded XSS payloads such as %3Cscript%3E or %3Cimg%20src targeting the administrative endpoint
Unexpected outbound requests from administrator browsers to unfamiliar domains shortly after visiting admin panel URLs
Session tokens or cookies appearing in web server referrer logs to external hosts

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect request parameters to /admin/*.php for common XSS patterns
Enable Content Security Policy (CSP) violation reporting to surface inline script execution attempts
Correlate access logs for administrator accounts against unusual referrer URLs or query strings containing HTML tags

Monitoring Recommendations

Monitor administrative endpoint access for anomalous parameter values and encoded script payloads
Alert on administrator sessions originating from unusual IP addresses or geolocations following suspicious URL clicks
Log and review all changes made through the admin panel that follow requests to makeDiy_deal.php

How to Mitigate CVE-2026-88746

Immediate Actions Required

Restrict access to /admin/ paths using IP allowlisting or VPN-only access until a patch is applied
Instruct administrators to avoid clicking untrusted links while authenticated to the idccms panel
Enable a strict Content Security Policy that disallows inline scripts and untrusted script sources
Rotate administrator credentials and invalidate active sessions if suspicious activity is observed

Patch Information

No official vendor patch is referenced in the published advisory at the time of NVD publication. Monitor the GitHub XSS Vulnerability Report and vendor channels for updates. Until a fix is released, apply compensating controls at the web server and WAF layers.

Workarounds

Configure a WAF or reverse proxy to block requests to /admin/makeDiy_deal.php containing HTML metacharacters or script keywords
Add an HTTP Content-Security-Policy header with default-src 'self'; script-src 'self' to reduce inline script execution
Set the HttpOnly and Secure flags on session cookies to limit token theft via JavaScript
Enforce short administrator session lifetimes and require re-authentication for sensitive actions

bash

# Example nginx configuration to add CSP and cookie hardening
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'" always;
add_header X-XSS-Protection "1; mode=block" always;
add_header X-Content-Type-Options "nosniff" always;

# Block obvious XSS payloads targeting the vulnerable endpoint
location = /admin/makeDiy_deal.php {
    if ($args ~* "(<|%3C)(script|img|svg|iframe)") {
        return 403;
    }
}