CVE-2026-7610: TRENDnet TEW-821DAP Information Disclosure

CVE-2026-7610 Overview

CVE-2026-7610 is an information disclosure vulnerability affecting the TRENDnet TEW-821DAP wireless access point running firmware version 1.12B01. The flaw resides in an unspecified function within the /www/cgi/ssi file used by the Firmware Update component. The vulnerability transmits sensitive information in cleartext during firmware update operations, classified under [CWE-310] Cryptographic Issues. Attackers can exploit this remotely, but the attack carries high complexity and is reported as difficult to execute. TRENDnet has confirmed that the affected hardware reached end-of-life status approximately eight years ago and will not receive security updates.

Critical Impact
Sensitive information transmitted during firmware updates can be intercepted by network-positioned attackers, exposing credentials or configuration data on an unsupported device with no vendor patch path.

Affected Products

TRENDnet TEW-821DAP hardware version v1.xR
TRENDnet TEW-821DAP firmware 1.12B01
End-of-life products no longer maintained by the vendor

Discovery Timeline

2026-05-02 - CVE-2026-7610 published to NVD
2026-05-06 - Last updated in NVD database

Technical Details for CVE-2026-7610

Vulnerability Analysis

The TEW-821DAP exposes a Server Side Includes (SSI) endpoint at /www/cgi/ssi that handles firmware update operations. During these operations, the device transmits sensitive information in cleartext over the network. An attacker positioned to observe network traffic between an administrator and the device can capture this data.

The issue maps to [CWE-310], reflecting a class of cryptographic weakness rather than a specific protocol flaw. The vulnerability affects only the firmware update workflow, which limits the practical attack window. Exploitation is rated as difficult because an attacker must observe traffic precisely when an administrator performs a firmware update.

TRENDnet declared the product end-of-life approximately eight years prior to publication. The vendor will not release a patch, leaving any deployed devices permanently exposed.

Root Cause

The root cause is the absence of transport-layer encryption for sensitive data exchanged through the /www/cgi/ssi Firmware Update component. The device relies on plaintext HTTP for management traffic that should be protected with TLS or equivalent encryption.

Attack Vector

The attack vector is network-based and requires the attacker to intercept traffic between an administrator and the access point during a firmware update. This typically requires a position on the same local network segment, an upstream network tap, or compromise of an intermediary device. No authentication or user interaction beyond the legitimate update operation is required from the victim.

No proof-of-concept exploit code or public exploitation tooling has been verified. Technical write-ups are available in the GitHub Firmware Update Guide and VulDB Vulnerability #360567.

Detection Methods for CVE-2026-7610

Indicators of Compromise

Plaintext HTTP requests to /www/cgi/ssi originating from administrative hosts to TEW-821DAP devices
Unexpected firmware update sessions or repeated firmware download attempts on the management network
Passive network captures showing credentials or configuration data adjacent to TEW-821DAP traffic

Detection Strategies

Inventory the network for TRENDnet TEW-821DAP devices using HTTP banner fingerprints and CPE match cpe:2.3:h:trendnet:tew-821dap:1.0r
Inspect traffic to TCP/80 on identified devices for cleartext credentials or session tokens during firmware updates
Correlate administrative login events with subsequent unencrypted firmware update sessions to identify exposure windows

Monitoring Recommendations

Capture and review network flows between administrative workstations and access points for unencrypted management protocols
Alert on any access to /www/cgi/ssi from non-administrative source addresses
Track end-of-life device inventory and flag continued production use for risk review

How to Mitigate CVE-2026-7610

Immediate Actions Required

Identify and decommission TRENDnet TEW-821DAP devices running firmware 1.12B01, as no vendor patch will be issued
Replace affected hardware with a currently supported wireless access point that enforces HTTPS for management
Restrict management access to the device through a dedicated, isolated VLAN until replacement is complete

Patch Information

No patch is available. TRENDnet has stated that the TEW-821DAP v1.xR hardware reached end-of-life approximately eight years ago and is no longer sold or maintained. The vendor will not release firmware updates addressing CVE-2026-7610. Hardware replacement is the only complete remediation.

Workarounds

Perform firmware updates only over an isolated, trusted physical link disconnected from production traffic
Place the device behind a reverse proxy that terminates TLS and restricts access to authenticated administrators
Block external and lateral access to the device management interface using firewall rules and segmentation
Rotate any credentials previously transmitted to the device after exposure assessment

bash

# Example firewall rule limiting management access to a single admin host
iptables -A FORWARD -p tcp -d <TEW-821DAP_IP> --dport 80 -s <ADMIN_HOST_IP> -j ACCEPT
iptables -A FORWARD -p tcp -d <TEW-821DAP_IP> --dport 80 -j DROP