Security Advisory: Weak Password Hashing Mechanism in TP-Link Deco M5 (CVE-2026-5040)

Vulnerability and Impact Description:

CVE-2026-5040

TP-Link Deco M5 v1 uses a weak password hashing mechanism to store user credentials. An attacker who obtains the password hash through system compromise or privileged access could perform brute-force or dictionary attacks.

Successful exploitation may result in disclosure of authentication credentials, enabling unauthorized access to device management functions, depending on the privileges associated with the recovered password. The primary security impact is loss of confidentiality.

CVSS v4.0 Score: 7.1 / High

CVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/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 Deco M5 | TP-Link

US: Download for Deco M5 | 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 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.