CVE-2026-75491

Description

Cudy TR3000 before 2.5.42 contains an authentication bypass vulnerability in the Mosquitto plugin auth_plugin_jwt.so that accepts unsigned JWTs using alg none. Attackers holding any Cudy-trusted client certificate can authenticate as admincudydevice on port 8883 and publish batchcmd requests to execute commands as root.

References

• https://d1jvyy13vm72kv.cloudfront.net/device/upgrade/m_upgrade_TR3000_256MB_Flash-R103-2.5.42-20261103-160202-sysupgrade_82672.zip
• https://www.cudy.com/en-us/pages/download-center/tr3000-1-0
• https://www.vulncheck.com/advisories/cudy-tr3000-before-2.5.42-mqtt-jwt-authentication-bypass-via-alg-none-tokens