CVE-2026-76653 in Archer MR600
Summary
by MITRE • 09/10/2026
A missing authentication vulnerability in the VPN configuration management has been identified in Archer MR600 (v2, v3 & v5) and TL-MR6400 v8 due to improper access control; a remote unauthenticated attacker may be able to access and modify VPN configuration information without valid credentials.
Successful exploitation may allow a remote unauthenticated attacker to disclose and modify VPN configuration information.
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Analysis
by VulDB Data Team • 09/10/2026
The identified vulnerability represents a critical failure in the authentication mechanisms governing the Virtual Private Network (VPN) configuration management interface on TP-Link Archer MR600 models v2, v3, and v5, as well as the TL-MR6400 model v8. This flaw stems from improper access control implementation within the device's web-based administrative interface or underlying API endpoints responsible for handling VPN settings. Specifically, the system fails to enforce mandatory authentication checks before processing requests related to viewing or altering VPN parameters. Consequently, any remote actor with network connectivity to the target device can interact with these configuration modules without providing valid credentials, effectively bypassing the intended security perimeter designed to protect sensitive administrative functions.
From a technical perspective, this vulnerability is classified under CWE-287, which denotes Improper Authentication, and more specifically aligns with CWE-306 regarding Missing Authentication for Critical Function. The absence of an authentication gate allows unauthenticated actors to send crafted HTTP requests or API calls that the device processes as legitimate administrative actions. This lack of verification means that the integrity of the VPN configuration is not protected against unauthorized modification. An attacker can exploit this by manipulating routing tables, changing encryption keys, altering server endpoints, or disabling security features entirely. Such modifications are executed with full administrative privileges because the system assumes any request reaching these specific management functions originates from an authorized administrator due to the missing verification step.
The operational impact of exploiting this vulnerability is severe and multifaceted. First, it allows for the disclosure of sensitive network topology information contained within VPN configurations, including internal IP ranges, DNS settings, and potentially embedded credentials or certificates if stored in plaintext or weakly encrypted formats. Second, and more critically, an attacker can modify these configurations to redirect traffic through malicious endpoints, facilitating man-in-the-middle attacks where they can intercept, decrypt, or alter communications passing through the VPN tunnel. This compromises the confidentiality and integrity of all data transmitted over the network protected by that specific VPN configuration. Furthermore, persistent modification could lead to a denial of service if critical connectivity parameters are removed or corrupted, effectively isolating users from their intended remote resources or exposing internal networks to external threats by disabling necessary access controls.
This vulnerability maps directly to several tactics and techniques within the MITRE ATT&CK framework. It aligns with T1078 Valid Accounts in the context of privilege escalation through misconfiguration, although technically it is an unauthenticated entry point that mimics authorized access. More accurately, it falls under TA0005 Defense Evasion as it allows attackers to bypass security controls without detection by standard authentication logs. The exploitation technique corresponds to T1190 Exploit Public-Facing Application, where the attacker leverages a flaw in an internet-facing service to gain initial foothold or lateral movement capabilities within the network infrastructure protected by the compromised router.
To mitigate this risk, immediate action is required from device owners and administrators. The primary remediation strategy involves applying any available firmware updates provided by TP-Link that address these specific access control flaws. Users should verify their current firmware version against the vendor's security advisories for the Archer MR600 and TL-MR6400 series. If no patch is immediately available, temporary mitigations include restricting physical or network-level access to the administrative interface using firewall rules if possible, changing default passwords to strong unique credentials, and disabling remote management features entirely unless absolutely necessary. Additionally, organizations should monitor for unusual changes in VPN configurations via logging mechanisms where supported, ensuring that any unauthorized modifications are detected promptly. Regular security audits of IoT device configurations are essential to prevent such misconfigurations from persisting in production environments.