Security Advisory on Denial-of-Service Vulnerability in UPnP Component of TP Link's TL-WR841N (CVE-2026-3622)

Vulnerability and Impact Description:

CVE-2026-3622

The vulnerability exists in the UPnP component of TL-WR841N v14, where improper input validation leads to an out-of-bounds read, potentially causing a crash of the UPnP service.

Successful exploitation can cause the UPnP service to crash, resulting in a Denial-of-Service condition.

CVSS v4.0 Score: 7.1 / High

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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. Download and update to the latest firmware version to fix the vulnerability:

EN: Download for TL-WR841N | TP-Link

US: Download for TL-WR841N | TP-Link

Workaround:

Disable UPnP, if operationally feasible, may reduce exposure until updated firmware is deployed.

Disclaimer:

If you do not take all recommended actions, this vulnerability will remain. TP-Link cannot bear any responsibility for consequences that could have been avoided by following this advisory.