CVE-2026-49186
MQTT Broker Topic ACL Bypass via Wildcard Subscriptions
Publication date: 2026-06-04
Last updated on: 2026-06-04
Assigner: 8fc372e3-d9c5-46e4-9410-38469745c639
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| acer | connect_m6e_5g_portable_wifi_router | to m6e_ai_1.00.000019 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-287 | When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability in the local MQTT broker, which does not enforce topic-level Access Control Lists (ACLs), allows unauthorized clients to subscribe to or publish messages using wildcard characters. This can lead to enumeration of hidden network devices and the sending of rogue control commands.
Such unauthorized access and potential manipulation of device configurations and communications could result in exposure or compromise of sensitive data, which may negatively impact compliance with data protection regulations like GDPR and HIPAA that require strict access controls and protection of personal or sensitive information.
Therefore, until the vulnerability is patched, affected devices may not meet the security requirements mandated by these common standards and regulations.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability immediately, users should secure their devices with strong administrative passwords and restrict IPv6 traffic where possible.
Additionally, users are advised to apply the forthcoming firmware patches via the device management interface as soon as they become available.
Can you explain this vulnerability to me?
This vulnerability exists because the local MQTT broker does not enforce topic-level Access Control Lists (ACLs).
As a result, any client connected to the broker can subscribe to topics using wildcard characters (# or +), which allows them to enumerate hidden network devices.
Additionally, clients can publish rogue control commands to the broker, potentially manipulating devices or services.
How can this vulnerability impact me? :
The vulnerability can lead to unauthorized discovery of hidden network devices by malicious clients.
It also allows attackers to send unauthorized control commands, which could disrupt device operations or compromise system integrity.
Overall, this can result in increased risk of network reconnaissance, unauthorized control, and potential service disruption.