Security Advisory: Unauthenticated Remote Code Execution in TP-Link TL-WR940N RTSP Conntrack Feature (CVE-2026-12935)

Vulnerability and Impact Description:

CVE-2026-12935

The TL-WR940N v6 router contains a vulnerability in its RTSP connection tracking module that can lead to a stack-based buffer overflow. The issue occurs when a LAN client initiates a connection to a malicious RTSP server controlled by an attacker. A specially crafted RTSP message may trigger improper memory handling within the kernel module

Successful exploitation of this vulnerability may result in a denial-of-service (DoS) condition or allow remote code execution (RCE), potentially leading to full compromise of the device. This vulnerability can be exploited by an unauthenticated attacker under the device's default configuration.

CVSS v4.0 Score: 8.7 / High

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Affected Products/Versions and Fixes:

Recommendations:

We strongly recommend that users with affected devices take the following actions:

1. Update affected devices to the latest firmware version that fixed the vulnerability:

EN: Download for TL-WR940N | TP-Link

US: Download for TL-WR940N | TP-Link

JP: Download for TL-WR940N | TP-Link

Disclaimer:

This advisory is provided for informational purposes only and is subject to change without notice. The information is provided “as is” without warranties of any kind. TP-Link recommends that customers promptly apply available firmware updates or implement documented workarounds as provided in this advisory. Devices/systems that are not updated or mitigated as described may remain vulnerable, and TP-Link disclaims any responsibility or liability for any damages or losses arising from a failure to implement such updates.