CVE-2026-44725 in EMQX
Summary
by MITRE • 08/20/2026
EMQX is a scalable and reliable MQTT broker for AI, IoT, IIoT, and connected vehicles. Prior to versions 5.8.11, 5.9.3, 5.10.4, 6.0.3, 6.1.2, and 6.2.1, the plugin-install REST API and dashboard upload accepted stale grants created with emqx ctl plugins allow because there was no five-minute grant lifetime or SHA-256 package binding. An attacker with a compromised dashboard administrator credential or API key with plugin-install permission who finds a stale allowed name and version can upload attacker-controlled bytes under the allowed .tar.gz filename through POST /api/v5/plugins/install or the dashboard plugin upload. The broker then installs and runs attacker-controlled Erlang code with the privileges of the EMQX process. This issue is fixed in versions 5.8.11, 5.9.3, 5.10.4, 6.0.3, 6.1.2, and 6.2.1.
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Analysis
by VulDB Data Team • 08/20/2026
EMQX serves as a critical infrastructure component for scalable MQTT messaging in AI, IoT, IIoT, and connected vehicle ecosystems. A severe security vulnerability was identified within the plugin installation mechanisms of EMQX versions prior to 5.8.11, 5.9.3, 5.10.4, 6.0.3, 6.1.2, and 6.2.1. This flaw resides in both the REST API endpoint for plugin installation and the corresponding dashboard upload functionality. The core technical deficiency involves the handling of authorization grants used to permit plugin uploads. Specifically, these grants lacked a five-minute expiration lifetime and did not implement SHA-256 package binding. Consequently, once an administrator or user with appropriate permissions generated a grant allowing a specific plugin name and version, that grant remained valid indefinitely until manually revoked or the service restarted. This design failure allowed for the reuse of stale authorization tokens, creating a window where previously approved actions could be executed under different circumstances than originally intended by the system administrators.
The operational impact of this vulnerability is severe due to its potential for remote code execution with elevated privileges. An attacker who has obtained compromised credentials for a dashboard administrator account or an API key possessing plugin-install permissions can exploit this flaw. By identifying a stale allowed name and version from previous legitimate operations, the attacker can craft a malicious payload disguised as a .tar.gz file that matches the permitted metadata but contains arbitrary Erlang code. Through POST requests to /api/v5/plugins/install or via the dashboard interface, the attacker uploads this controlled content. Because EMQX processes plugin installations by executing them within its own runtime environment, the broker proceeds to install and run the attacker-controlled Erlang code with the same privileges as the main EMQX process. This effectively grants the attacker full control over the underlying system hosting the MQTT broker, enabling data exfiltration, lateral movement across IoT networks, or complete denial of service by disrupting critical messaging services.
From a classification perspective, this vulnerability aligns with CWE-284 Improper Access Control and CWE-613 Insufficient Session Expiration due to the lack of time-bound validity for authorization grants. Furthermore, it facilitates ATT&CK technique T1059 Command and Scripting Interpreter through Erlang code execution, allowing adversaries to establish persistence or escalate privileges within the containerized or host environment running EMQX. The absence of SHA-256 package binding also relates to CWE-347 Improper Verification of Cryptographic Signature, as there was no cryptographic assurance that the uploaded file matched the specific artifact originally authorized by the grant mechanism. This combination of weaknesses allows for a straightforward privilege escalation path from authenticated API access to arbitrary code execution on the broker host.
Mitigation requires immediate action to upgrade EMQX instances to patched versions 5.8.11, 5.9.3, 5.10.4, 6.0.3, 6.1.2, or 6.2.1, where the grant lifetime is enforced and package binding via SHA-256 hashes has been implemented to ensure integrity. In environments where immediate patching is not feasible, administrators should rotate all dashboard administrator credentials and API keys with plugin-install permissions to invalidate any existing stale grants. Additionally, restricting network access to the EMQX management interfaces through firewall rules or reverse proxy authentication can reduce the attack surface. Regular auditing of installed plugins and monitoring for unexpected Erlang processes or resource consumption spikes can aid in early detection of exploitation attempts. Ensuring that only trusted sources are permitted for plugin installation and enforcing strict least-privilege principles on API keys further mitigates the risk associated with this class of vulnerabilities.