CVE-2026-75491
Cudy TR3000 before 2.5.42 MQTT JWT Authentication Bypass via alg none Tokens
CVE-2026-75491 is a critical vulnerability (CVSS 9.2) in Shenzhen Cudy Technology Co., Ltd. Tr3000 1.0, published November 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 15th percentile. No source names a fixed version.
- Severity
- 9.2 CriticalCVSS 4.0, CVE List
- Exploit chance
- 0.25%EPSS, 15th percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
Affected products
What each source reports
CVE List Score used
Cudy TR3000 before 2.5.42 MQTT JWT Authentication Bypass via alg none Tokens
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.
- Record
CVE-2026-75491- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-347
- Updated
- 2026-11-13
EUVDEUVD-2026-125265
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.
- Record
EUVD-2026-125265- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-13
GitHub AdvisoriesGHSA-3whc-7xhg-h8j2
Cudy TR3000 before 2.5.42 contains an authentication bypass vulnerability in the Mosquitto plugin...
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.
- Record
GHSA-3whc-7xhg-h8j2- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-347
- Updated
- 2026-11-13
NVD
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.
- Record
CVE-2026-75491- CVSS 4.0
- 9.2 Critical
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-347
- Updated
- 2026-11-13
History
| Recorded | Changed | Sources |
|---|---|---|
| published | EUVD | |
| published | EUVD | |
| aliases, references | GitHub Advisories, NVD | |
| aliases, published | EUVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
cudy.com/en-us/pages/download-center/tr3000-1-0
d1jvyy13vm72kv.cloudfront.net/device/upgrade/m_upgrade_TR3000_256MB_Flash-R103-2.5.42-20261103-160202-sysupgrade_82672.zip
vulncheck.com/advisories/cudy-tr3000-before-2.5.42-mqtt-jwt-authentication-bypass-via-alg-none-tokens
nvd.nist.gov/vuln/detail/CVE-2026-75491
github.com/advisories/GHSA-3whc-7xhg-h8j2