CVE-2025-26326: NVDA Remote Auth Bypass Vulnerability

CVE-2025-26326 Overview

A critical weak authentication vulnerability has been identified in NVDA Remote (version 2.6.4) and Tele NVDA Remote (version 2025.3.3) add-ons for the NVDA screen reader. This vulnerability allows remote attackers to gain complete control of affected systems by guessing weak passwords used for remote connections.

The NVDA (NonVisual Desktop Access) screen reader is an open-source application designed to assist visually impaired users. The remote connection add-ons extend NVDA's functionality by allowing remote assistance and collaboration. However, these add-ons accept any password entered by users without implementing additional authentication mechanisms or computer verification, making them susceptible to brute force attacks.

Research indicates that more than 1,000 systems in the wild use easily guessable passwords, many consisting of fewer than 4 to 6 characters, including common sequences. This significantly lowers the barrier for exploitation.

Critical Impact

Successful exploitation grants attackers complete access to vulnerable systems, enabling command execution, file modification, and full compromise of user security.

Affected Products

• NVDA Remote version 2.6.4
• Tele NVDA Remote version 2025.3.3
• Systems using weak or easily guessable passwords for NVDA Remote connections

Discovery Timeline

• February 28, 2025 - CVE-2025-26326 published to NVD
• April 15, 2026 - Last updated in NVD database

Technical Details for CVE-2025-26326

Vulnerability Analysis

This vulnerability is classified under CWE-287 (Improper Authentication). The core issue stems from the remote connection add-ons' failure to enforce any password complexity requirements or implement secondary authentication mechanisms. When a user configures a remote connection, the add-ons accept whatever password is provided without validation, regardless of strength.

The attack surface is particularly concerning because it requires no special privileges from the attacker's perspective and can be executed entirely over the network. The only prerequisite is user interaction—specifically, the victim must have an active remote connection session. Once an attacker successfully guesses or brute-forces the password, they achieve the same level of access as the legitimate remote user.

Root Cause

The root cause is the absence of authentication hardening in the NVDA Remote and Tele NVDA Remote add-ons. Specifically:

1. No password policy enforcement: The add-ons accept any password without minimum length or complexity requirements
2. Missing rate limiting: No protection against rapid, repeated authentication attempts
3. Lack of multi-factor authentication: No secondary verification mechanism to validate connection requests
4. No computer/device verification: The add-ons do not verify the identity of connecting machines beyond the shared password

Attack Vector

The attack can be executed remotely over a network connection. An attacker who knows or can deduce the target's connection password can connect to the victim's NVDA Remote session and gain full system access.

The exploitation process involves:

1. Identifying systems running NVDA Remote add-ons with active connections
2. Attempting to connect using commonly used weak passwords
3. Systematically trying password variations through brute force or dictionary attacks
4. Upon successful authentication, gaining complete control of the remote system

A proof-of-concept demonstrating this vulnerability is available at the GitHub PoC Repository for CVE-2025-26326.

Detection Methods for CVE-2025-26326

Indicators of Compromise

• Unexpected NVDA Remote connection attempts or successful connections from unknown IP addresses
• Multiple failed authentication attempts to NVDA Remote services in rapid succession
• Unusual system activity or command execution coinciding with NVDA Remote sessions
• Log entries showing connection attempts from geographic locations inconsistent with legitimate users

Detection Strategies

• Monitor network traffic for connections to NVDA Remote services from unauthorized sources
• Implement logging for all NVDA Remote connection attempts, both successful and failed
• Deploy endpoint detection tools to alert on suspicious process execution during remote sessions
• Review system event logs for anomalies during times when NVDA Remote is active

Monitoring Recommendations

• Enable verbose logging for NVDA Remote add-on activities
• Configure network intrusion detection systems to alert on brute force patterns targeting accessibility software ports
• Establish baseline connection patterns for legitimate NVDA Remote usage and alert on deviations
• Periodically audit password strength across all NVDA Remote installations in the environment

How to Mitigate CVE-2025-26326

Immediate Actions Required

• Audit all NVDA Remote and Tele NVDA Remote installations for weak passwords and enforce strong password policies
• Consider disabling NVDA Remote functionality until patches addressing authentication weaknesses are available
• Implement network-level access controls to restrict NVDA Remote connections to trusted IP addresses
• Educate users on the importance of strong, unique passwords for remote accessibility tools

Patch Information

As of the last NVD update, users should monitor the official repositories for security updates:

• NVDA Remote GitHub Repository
• Tele NVDA GitHub Repository
• NVDA Add-ons Portal
• NVDARemote Official Website
• NV Access Official Site

Users are strongly encouraged to update to the latest versions as soon as security patches become available.

Workarounds

• Use strong passwords with a minimum of 12 characters, including uppercase, lowercase, numbers, and special characters
• Restrict NVDA Remote connections to VPN-protected networks only
• Implement host-based firewall rules to limit which IP addresses can connect to NVDA Remote services
• Consider using alternative remote assistance solutions with stronger authentication mechanisms until this vulnerability is addressed