CVE-2026-5039: Predictable Default Cryptographic Key Used for DES Encryption in TP-Link TL-WL841N
TP-Link TL-WR841N v13 uses DES-CBC encryption in the TDDPv2 debug protocol with a cryptographic key derived from default web management credentials, making the key predictable if device is left in default configuration. A network-adjacent attacker can exploit this weakness to gain unauthorized access to the protocol, read debug data, modify certain device configuration values, and trigger device reboot, resulting in loss of integrity and a denial-of-service condition.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-5039?
CVE-2026-5039 is considered a high severity vulnerability due to its potential to expose sensitive data through predictable encryption keys.
How do I fix CVE-2026-5039?
To fix CVE-2026-5039, change the default web management credentials and ensure that the device is configured with a strong, non-default password.
What devices are affected by CVE-2026-5039?
CVE-2026-5039 affects the TP-Link TL-WR841N version 13 and potentially other models using the same vulnerability.
What type of encryption is exploited in CVE-2026-5039?
CVE-2026-5039 exploits DES-CBC encryption in the TDDPv2 debug protocol, which utilizes a predictable default cryptographic key.
What happens if CVE-2026-5039 is not addressed?
If CVE-2026-5039 is not addressed, attackers could gain unauthorized access to encrypted data by exploiting the predictable cryptographic key.