CVE-2026-25595: InvoicePlane XSS Vulnerability

CVE-2026-25595 Overview

A Stored Cross-Site Scripting (XSS) vulnerability has been identified in InvoicePlane version 1.7.0, a self-hosted open source application used for managing invoices, clients, and payments. The vulnerability exists in the Invoice Number field, allowing an authenticated administrator to inject malicious JavaScript code that executes when any administrator views the affected invoice or accesses the dashboard.

Critical Impact

Malicious JavaScript persists in the database and executes in the browser context of administrators viewing invoices or the dashboard, potentially leading to session hijacking, credential theft, or unauthorized actions.

Affected Products

• InvoicePlane version 1.7.0

Discovery Timeline

• 2026-02-18 - CVE CVE-2026-25595 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-25595

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability (CWE-79) allows authenticated administrators to inject persistent malicious JavaScript into the Invoice Number field within InvoicePlane. Unlike reflected XSS attacks, this stored variant persists in the application database, meaning the payload executes every time an administrator views the compromised invoice or navigates to the dashboard where invoice data is displayed.

The attack requires high privileges (administrator access) and user interaction (a victim administrator must view the affected content). However, the scope is changed as the vulnerability can affect resources beyond the vulnerable component—specifically, other administrators' browser sessions. This enables potential attacks including session cookie exfiltration, keylogging, DOM manipulation, and execution of unauthorized administrative actions on behalf of victim users.

Root Cause

The root cause of this vulnerability is insufficient input sanitization and output encoding in the Invoice Number field. When administrators create or modify invoices, the application fails to properly sanitize special characters and HTML/JavaScript content before storing the data. Additionally, when rendering invoice information on the dashboard or invoice detail pages, the application does not properly encode the output, allowing stored scripts to execute in the browser context.

Attack Vector

The attack is network-based and requires an authenticated administrator account. An attacker with administrator credentials can craft a malicious Invoice Number containing JavaScript code. This payload is stored in the database and subsequently rendered without proper encoding when other administrators view the invoice or dashboard. The malicious script then executes in the victim's browser session with full access to the page DOM and session cookies.

The exploitation mechanism involves inserting script tags or event handlers into the Invoice Number field. When the vulnerable page renders, the browser interprets the stored content as executable code rather than display text.

Detection Methods for CVE-2026-25595

Indicators of Compromise

• Review invoice records in the database for suspicious content in the Invoice Number field, including <script> tags, event handlers (e.g., onerror, onload), or encoded JavaScript
• Examine web server logs for unusual POST requests to invoice creation/modification endpoints containing potential XSS payloads
• Monitor for unexpected outbound network connections from administrator browsers when viewing invoices

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in form submissions
• Deploy Content Security Policy (CSP) headers to restrict inline script execution and report violations
• Enable browser-side XSS auditing and monitor for blocked script execution attempts

Monitoring Recommendations

• Enable detailed audit logging for all invoice creation and modification actions
• Monitor database fields for injection of HTML tags and JavaScript patterns
• Configure CSP reporting to capture and alert on policy violations that may indicate exploitation attempts

How to Mitigate CVE-2026-25595

Immediate Actions Required

• Upgrade InvoicePlane to version 1.7.1 immediately, which patches this vulnerability
• Audit existing invoice records for suspicious Invoice Number values containing script content
• Implement Content Security Policy headers to mitigate potential exploitation before patching
• Review administrator accounts for any unauthorized access or suspicious activity

Patch Information

InvoicePlane has released version 1.7.1 to address this vulnerability. The fix implements proper input validation and output encoding for the Invoice Number field. The patch can be obtained from the official InvoicePlane repository. For technical details on the fix, refer to the GitHub commit and the GitHub Security Advisory GHSA-xxvr-2564-6jg6.

Workarounds

• Implement strict Content Security Policy headers to prevent inline script execution: Content-Security-Policy: script-src 'self';
• Apply input validation at the web server or reverse proxy level to reject requests containing script tags in invoice fields
• Restrict administrative access to trusted users only until the patch can be applied
• Consider temporarily disabling invoice creation/modification functionality if immediate patching is not possible

# Example Apache configuration to add CSP headers as a temporary mitigation
# Add to your InvoicePlane .htaccess or virtual host configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"
Header set X-XSS-Protection "1; mode=block"
Header set X-Content-Type-Options "nosniff"