CVE-2026-24838
📋 TL;DR
This vulnerability allows attackers to inject malicious scripts into DNN module titles, which execute in users' browsers when viewing affected pages. It affects all DNN installations prior to versions 9.13.10 and 10.2.0. Attackers can steal session cookies, redirect users, or perform actions on their behalf.
💻 Affected Systems
- DNN Platform (formerly DotNetNuke)
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, data theft, and persistent site compromise through stored XSS payloads that affect all users viewing vulnerable pages.
Likely Case
Session hijacking, credential theft, and unauthorized actions performed in users' contexts when they view malicious module titles.
If Mitigated
Limited impact with proper input validation and output encoding, but still presents risk if rich text features are enabled.
🎯 Exploit Status
Exploitation requires authenticated access with module editing permissions, but once injected, scripts execute for all users viewing affected pages.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.13.10 or 10.2.0
Vendor Advisory: https://github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-w9pf-h6m6-v89h
Restart Required: Yes
Instructions:
1. Backup your DNN installation and database. 2. Download DNN Platform version 9.13.10 or 10.2.0 from the official repository. 3. Follow the standard DNN upgrade procedure for your version. 4. Restart the application pool in IIS. 5. Verify the upgrade completed successfully.
🔧 Temporary Workarounds
Disable Rich Text in Module Titles
windowsTemporarily disable rich text editing for module titles to prevent script injection.
Modify web.config or site settings to disable HTML/rich text in module title fields
Implement Output Encoding
windowsAdd server-side output encoding for all module title displays.
Implement HttpUtility.HtmlEncode() or similar encoding for module title output
🧯 If You Can't Patch
- Implement strict input validation to reject HTML/script content in module titles
- Deploy a web application firewall (WAF) with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check DNN version in Host Settings > Site Settings > Basic Settings, or examine the /Portals/_default/About.aspx page.Check Version:
Check the 'ProductVersion' value in web.config or view /Portals/_default/About.aspxVerify Fix Applied:
Verify version is 9.13.10 or higher (for 9.x) or 10.2.0 or higher (for 10.x) in Host Settings.📡 Detection & Monitoring
Log Indicators:
- Unusual module title updates containing script tags
- Multiple failed login attempts followed by module edits
Network Indicators:
- Unexpected JavaScript execution in module title contexts
- Suspicious outbound connections from DNN pages
SIEM Query:
source="dnn_logs" AND (event="module_update" AND title CONTAINS "<script") OR (event="page_view" AND referrer CONTAINS suspicious_domain)