CVE-2025-66024: XWiki Blog Application XSS Vulnerability

CVE-2025-66024 Overview

CVE-2025-66024 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the XWiki blog application. The vulnerability exists in versions prior to 9.15.7 and allows attackers with blog post creation or editing permissions to inject malicious JavaScript code into the blog post title field. When any user, including administrators, views the affected blog post, the malicious script executes in their browser context.

The vulnerability arises because the post title is injected directly into the HTML <title> tag without proper escaping. This flaw enables potential session hijacking and privilege escalation attacks against XWiki platform users.

Critical Impact

Authenticated attackers can inject persistent malicious JavaScript that executes in the browsers of all users viewing the blog post, including administrators, enabling session hijacking and privilege escalation.

Affected Products

• XWiki Blog Application versions prior to 9.15.7

Discovery Timeline

• March 4, 2026 - CVE-2025-66024 published to NVD
• March 5, 2026 - Last updated in NVD database

Technical Details for CVE-2025-66024

Vulnerability Analysis

This Stored XSS vulnerability (CWE-79) occurs due to improper neutralization of input during web page generation. The XWiki blog application fails to sanitize user-supplied content in the blog post title field before rendering it within the HTML <title> element.

When an attacker crafts a malicious blog post title containing JavaScript code, that code is stored in the application database. Subsequently, whenever any user navigates to view the blog post, the unsanitized title content is rendered directly into the page's HTML structure. The browser interprets and executes the injected script with the same privileges as the viewing user's session.

The attack requires low privileges (authenticated user with blog editing permissions) and user interaction (victim must view the malicious blog post). However, once triggered, the consequences can be severe, including theft of session cookies, unauthorized actions performed on behalf of administrators, and potential compromise of the entire XWiki platform.

Root Cause

The root cause is missing output escaping when the blog post title is rendered in the HTML <title> tag. The application directly concatenates user-controlled input into the page template without applying HTML entity encoding or other sanitization measures. This allows special characters like <, >, and quotation marks to be interpreted as HTML/JavaScript syntax rather than as literal text.

Attack Vector

An attacker exploits this vulnerability through the following steps:

1. The attacker authenticates to the XWiki platform with permissions to create or edit blog posts
2. The attacker creates a new blog post or edits an existing one
3. In the title field, the attacker injects a malicious JavaScript payload designed to close the <title> tag and execute arbitrary script
4. The blog post is saved, storing the malicious payload in the database
5. When any user (including administrators) views the blog post, their browser renders the injected script
6. The malicious JavaScript executes in the victim's browser context, potentially stealing session tokens or performing unauthorized actions

The attack is particularly dangerous because it persists in the database and affects every user who views the compromised blog post. Administrators who routinely review blog content are high-value targets for privilege escalation attacks.

Detection Methods for CVE-2025-66024

Indicators of Compromise

• Unusual JavaScript code or HTML tags present in blog post titles within the XWiki database
• Blog post titles containing <script>, </title>, event handlers like onerror=, or encoded variants
• Unexpected outbound network requests from user browsers when viewing blog content
• Session anomalies or unauthorized administrative actions following blog post views

Detection Strategies

• Review XWiki blog post database entries for titles containing HTML tags or JavaScript syntax
• Implement Content Security Policy (CSP) headers to detect and block inline script execution attempts
• Monitor web application firewall (WAF) logs for XSS payload patterns in POST requests to blog endpoints
• Audit XWiki application logs for blog post creation or modification events with suspicious title content

Monitoring Recommendations

• Enable browser-based XSS auditing and CSP violation reporting to identify exploitation attempts
• Configure SIEM alerts for patterns indicative of session hijacking following blog interactions
• Periodically scan stored blog content for injection patterns using automated security scanning tools
• Monitor for unexpected privilege escalation events that correlate with blog post viewing activity

How to Mitigate CVE-2025-66024

Immediate Actions Required

• Upgrade the XWiki blog application to version 9.15.7 or later immediately
• Review existing blog posts for potentially malicious titles and sanitize or remove suspicious content
• Implement Content Security Policy headers to mitigate the impact of any unpatched XSS vulnerabilities
• Consider temporarily restricting blog post creation and editing permissions to trusted users until patching is complete

Patch Information

The vulnerability has been patched in XWiki blog application version 9.15.7. The fix adds proper HTML escaping when rendering blog post titles in the <title> tag. Organizations should update to this version or later as soon as possible.

For detailed patch information, refer to the GitHub Commit Update and the GitHub Security Advisory. Additional details are available in the XWiki Jira Issue BLOG-245.

Workarounds

• No vendor-provided workarounds are available for this vulnerability
• As a temporary measure, restrict blog post creation and editing permissions to highly trusted users only
• Implement strict Content Security Policy headers to reduce the impact of XSS attacks
• Deploy a Web Application Firewall (WAF) with XSS detection rules to filter malicious input patterns