CVE-2026-5039: tl-wr841n (CVSS 8.8)

Description

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.

Is your site exposed to CVE-2026-5039?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.04%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-1394 CWE-1394

Affected Products

Vendor	Product	Versions
tp-link	tl-wr841n_firmware	< 231120
tp-link	tl-wr841n	All

References

Other References

https://www.tp-link.com/us/support/download/tl-wr841n/v13/#Firmware

Frequently Asked Questions

What is CVE-2026-5039? +

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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-5039? +

CVE-2026-5039 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-5039? +

CVE-2026-5039 affects products from tp-link, specifically: tl-wr841n, tl-wr841n_firmware. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-5039? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-1275

Use of Default Cryptographic Key vulnerability in Baxter Welch Allyn Connex Spot Monitor may allow Configuration/Environment Manipulation.This issue affects Welch …

CVE-2024-48956 9.8

Serviceware Processes 6.0 through 7.3 before 7.4 allows attackers without valid authentication to send a specially crafted HTTP request to …

CVE-2025-41742 9.8

Sprecher Automations SPRECON-E-C, SPRECON-E-P, SPRECON-E-T3 is vulnerable to attack by an unauthorized remote attacker via default cryptographic keys. The use …

CVE-2026-75870 9.1

Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is …

CVE-2024-29037 9.1

datahub-helm provides the Kubernetes Helm charts for deploying Datahub and its dependencies on a Kubernetes cluster. Starting in version 0.1.143 …

CVE-2025-55049 9.1

Use of Default Cryptographic Key (CWE-1394)

CVE-2026-5039