CVE-2026-30867
5.7 · MEDIUMOverview
CVE-2026-30867 is a medium-severity vulnerability affecting emqx cocoamqtt. It was published on April 2, 2026 and has a CVSS 3.1 base score of 5.7 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.7, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical Description
CocoaMQTT is a MQTT 5.0 client library for iOS and macOS written in Swift. Prior to version 2.2.2, a vulnerability exists in the packet parsing logic of CocoaMQTT that allows an attacker (or a compromised/malicious MQTT broker) to remotely crash the host iOS/macOS/tvOS application. If an attacker publishes the 4-byte malformed payload to a shared topic with the RETAIN flag set to true, the MQTT broker will persist the payload. Any time a vulnerable client connects and subscribes to that topic, the broker will automatically push the malformed packet. The app will instantly crash in the background before the user can even interact with it. This effectively "bricks" the mobile application (a persistent DoS) until the retained message is manually wiped from the broker database. This issue has been patched in version 2.2.2.
Remediation
Check the references section for vendor advisories and patches from emqx. Update cocoamqtt to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| emqx | cocoamqtt | >= 0, < 2.2.2 | Affected |
Frequently Asked Questions
What is CVE-2026-30867?
CVE-2026-30867 is a medium-severity vulnerability affecting emqx cocoamqtt. It was published on April 2, 2026 and has a CVSS 3.1 base score of 5.7 (MEDIUM).
How severe is CVE-2026-30867?
This vulnerability has a CVSS 3.1 base score of 5.7, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-30867?
Check the references section for vendor advisories and patches from emqx. Update cocoamqtt to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-30867?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-30867 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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