CVE-2026-30816: TP-Link Archer AX53 Info Disclosure Flaw

CVE-2026-30816 Overview

CVE-2026-30816 is an external control of configuration vulnerability in the OpenVPN module of the TP-Link Archer AX53 v1.0 router. An authenticated attacker on an adjacent network can supply a malicious OpenVPN configuration file that causes the device to read arbitrary files. Successful exploitation exposes sensitive information stored on the device, including potentially credentials, configuration data, and system files.

The vulnerability is tracked under CWE-15: External Control of System or Configuration Setting and CWE-610: Externally Controlled Reference to a Resource in Another Sphere. It was disclosed in Talos Intelligence Report TALOS-2025-2304 and affects Archer AX53 v1.0 firmware before 1.7.1 Build 20260213.

Critical Impact

Authenticated adjacent attackers can read arbitrary files on affected TP-Link Archer AX53 v1.0 routers by submitting crafted OpenVPN configuration files, exposing sensitive device data.

Affected Products

• TP-Link Archer AX53 v1.0 firmware (versions before 1.7.1 Build 20260213)
• TP-Link Archer AX53 hardware revision v1.0
• OpenVPN module embedded in Archer AX53 firmware

Discovery Timeline

• 2026-04-08 - CVE-2026-30816 published to NVD
• 2026-05-07 - Last updated in NVD database

Technical Details for CVE-2026-30816

Vulnerability Analysis

The Archer AX53 v1.0 firmware permits authenticated users to upload OpenVPN configuration files to enable VPN server functionality. The OpenVPN module parses these configuration files without restricting which directives or file references the configuration may contain. An attacker on an adjacent network with valid credentials can craft a configuration file that references arbitrary file paths on the underlying Linux filesystem.

When the OpenVPN process loads the malicious configuration, it reads the referenced files and surfaces their contents through OpenVPN runtime behavior, log output, or error responses. This bypasses the intended boundary between user-supplied configuration values and the device's protected resources.

Root Cause

The root cause is improper validation of externally controlled configuration data [CWE-15] combined with externally controlled references to resources outside the expected sphere [CWE-610]. The firmware accepts OpenVPN directives such as those referencing certificate, key, or auxiliary files without constraining the file paths to a sandboxed directory. The OpenVPN module operates with elevated privileges on the router and can therefore access files outside the user's intended scope.

Attack Vector

Exploitation requires the attacker to be authenticated to the router's administrative interface and connected to an adjacent network such as the local LAN or Wi-Fi. The attacker submits a malicious OpenVPN configuration file through the VPN management interface. When the router processes the configuration, file paths controlled by the attacker are read and their contents are exposed back to the attacker. No user interaction is required beyond the normal VPN configuration workflow. The vulnerability does not allow modification of files, only disclosure.

No public proof-of-concept exploit code is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Talos Intelligence advisory for technical specifics on the affected OpenVPN directives.

Detection Methods for CVE-2026-30816

Indicators of Compromise

• Unexpected OpenVPN configuration uploads or modifications in router administrative logs from non-administrator accounts or unusual times.
• OpenVPN process log entries referencing file paths outside the expected VPN configuration directory, such as /etc/passwd, /etc/shadow, or device configuration backups.
• Anomalous outbound traffic from the router following VPN configuration changes, indicating potential exfiltration of disclosed file contents.

Detection Strategies

• Audit the router administrative interface for OpenVPN configuration uploads and compare submitted configurations against an allow-list of expected directives.
• Inspect router system logs for OpenVPN startup messages that reference unexpected file paths or report file read errors on system files.
• Monitor authenticated administrative sessions on the LAN side for sequences that include credential use followed by VPN module configuration changes.

Monitoring Recommendations

• Forward router syslog data to a centralized log platform and alert on OpenVPN configuration changes outside scheduled maintenance windows.
• Track firmware version reporting across the fleet of Archer AX53 v1.0 devices to identify hosts still running versions before 1.7.1 Build 20260213.
• Monitor for new or modified local user accounts on affected routers, since exploitation requires valid authentication.

How to Mitigate CVE-2026-30816

Immediate Actions Required

• Update Archer AX53 v1.0 firmware to version 1.7.1 Build 20260213 or later using the official TP-Link firmware download page.
• Rotate the router administrator password and any credentials stored in OpenVPN configurations after patching, in case prior exploitation occurred.
• Disable the OpenVPN server feature on affected devices until the patched firmware is applied.

Patch Information

TP-Link has released firmware version 1.7.1 Build 20260213 for the Archer AX53 v1.0 that resolves CVE-2026-30816. Download the firmware from the TP-Link Archer AX53 v1 firmware page or the regional TP-Link site. Consult the TP-Link Support FAQ for firmware upgrade procedures.

Workarounds

• Disable the OpenVPN server module in the router web interface to remove the vulnerable code path until firmware can be updated.
• Restrict administrative access to the router by limiting which LAN or Wi-Fi clients can reach the management interface, reducing the adjacent-network attack surface.
• Enforce strong, unique administrator credentials and disable any unused local accounts that could be leveraged to meet the authentication prerequisite.