CVE-2026-76649: CWE-476 NULL pointer dereference in TP-Link System Inc. TL-WR841N v14

This vulnerability (CVE-2026-76649) involves a NULL pointer dereference (CWE-476) in the UPnP service of the TP-Link TL-WR841N v14 router. When the UPnP daemon processes a SOAP action request containing unexpected XML content, it may dereference a NULL pointer, causing the daemon to crash. This leads to a denial-of-service condition impacting UPnP functionality until manual intervention (service restart or device reboot) occurs. The CVSS 4.0 vector indicates the attack requires adjacent network access with low complexity and no privileges or user interaction. No known exploits are reported in the wild, and no vendor-provided patch or mitigation guidance is currently documented.

Exploitation causes the UPnP daemon on the affected device to terminate unexpectedly, resulting in denial of service of UPnP features until the service is restarted or the device is rebooted. This disrupts UPnP functionality but does not indicate further compromise or privilege escalation. The impact is limited to availability of the UPnP service.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, affected users should consider restarting the UPnP service or rebooting the device if the service terminates unexpectedly. Network segmentation or limiting access to the UPnP service to trusted hosts may reduce exposure, but no official mitigation is documented.