CVE-2026-25230: FileRise HTML Injection XSS Vulnerability

CVE-2026-25230 Overview

CVE-2026-25230 is an HTML Injection vulnerability affecting FileRise, a self-hosted web file manager and WebDAV server. Prior to version 3.3.0, the application fails to properly sanitize user-supplied input, allowing authenticated users to inject arbitrary HTML content into the application's pages. This vulnerability enables attackers to modify the Document Object Model (DOM) to insert malicious form elements that can call backend endpoints or inject link elements that redirect users to attacker-controlled destinations upon interaction.

Critical Impact

Authenticated attackers can manipulate the web interface to deceive other users, potentially harvesting credentials through fake login forms or redirecting victims to malicious sites. This could lead to credential theft, phishing attacks, or further exploitation of the file management system.

Affected Products

• FileRise versions prior to 3.3.0
• Self-hosted FileRise WebDAV server installations
• All FileRise deployments without the security patch applied

Discovery Timeline

• 2026-02-09 - CVE CVE-2026-25230 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2026-25230

Vulnerability Analysis

This HTML Injection vulnerability (CWE-79) exists in FileRise's file handling components, specifically within FileController.php and FileModel.php. The vulnerability requires an authenticated user to exploit, meaning an attacker must have valid credentials to the FileRise instance. Once authenticated, the attacker can inject malicious HTML content that gets rendered in the context of other users' sessions.

The injection allows manipulation of the DOM structure, enabling attackers to insert form elements that submit data to arbitrary endpoints or create deceptive link elements. When other authenticated users interact with these injected elements, they may unknowingly disclose sensitive information or be redirected to malicious external resources.

The attack is network-accessible and requires user interaction for successful exploitation, as victims must actively engage with the injected content for the attack to succeed.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and output encoding within the FileRise application. The affected code in FileController.php (lines 4016-4058) and FileModel.php (line 3146) fails to properly sanitize user-controlled input before rendering it in HTML context. This allows HTML metacharacters to be interpreted as markup rather than being treated as literal text.

Attack Vector

The attack vector is network-based, requiring authenticated access to the FileRise application. An attacker with valid credentials can exploit this vulnerability by submitting specially crafted input containing HTML tags. The injected HTML is then stored or reflected in the application's pages, affecting other users who view the manipulated content.

The vulnerability mechanism involves injecting HTML elements such as <form> tags with custom action attributes pointing to attacker-controlled endpoints, or <a> tags with malicious href values. When victims interact with these elements, they may submit credentials to the attacker or be redirected to phishing sites. For detailed technical analysis, refer to the GitHub Security Advisory GHSA-h8fw-42v6-gfhv and the affected code locations in FileController.php and FileModel.php.

Detection Methods for CVE-2026-25230

Indicators of Compromise

• Unusual HTML tags or form elements appearing in file names, descriptions, or metadata fields
• User reports of unexpected redirects or unfamiliar login prompts within the FileRise interface
• Web server logs showing requests to unexpected external URLs originating from FileRise pages
• Presence of encoded HTML entities or script tags in user-controlled input fields

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing HTML injection patterns
• Monitor application logs for attempts to insert HTML tags in input fields that should contain plain text
• Deploy SentinelOne Singularity Platform to detect anomalous web application behavior and potential exploitation attempts
• Conduct regular security audits of user-generated content stored within FileRise

Monitoring Recommendations

• Enable detailed access logging on the FileRise web server to track user interactions and input submissions
• Configure alerting for authentication anomalies that may indicate credential theft from injected forms
• Monitor outbound network connections from the FileRise server for unexpected destinations
• Review application audit trails for suspicious file naming patterns or metadata changes

How to Mitigate CVE-2026-25230

Immediate Actions Required

• Upgrade FileRise to version 3.3.0 or later immediately to remediate this vulnerability
• Review existing file names and metadata for evidence of HTML injection attempts
• Audit user accounts with write access to identify potential malicious actors
• Consider temporarily restricting write access to trusted users until the patch is applied

Patch Information

The vulnerability has been fixed in FileRise version 3.3.0. The patch implements proper input sanitization and output encoding to prevent HTML content from being interpreted as markup. Users should upgrade to the patched version available at the FileRise v3.3.0 release page. The security advisory with full details is available at GHSA-h8fw-42v6-gfhv.

Workarounds

• Implement a reverse proxy with a WAF to filter malicious HTML patterns in requests
• Restrict FileRise access to trusted users only until the patch can be applied
• Deploy Content Security Policy (CSP) headers to limit the impact of injected content
• Disable or restrict features that allow user-controlled content to be displayed to other users

# Example WAF rule for Apache ModSecurity to block HTML injection attempts
SecRule ARGS "@rx <[a-zA-Z]+" "id:100001,phase:2,deny,status:403,msg:'Potential HTML Injection Attempt'"