CVEvulnerability

CVE-2026-30867

6.5 MEDIUM Published 2026-04-02 Modified 2026-10-26 Official page ↗
Status
Analyzed
Published
2026-04-02
Last modified
2026-10-26
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.7 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
CVSS 3.1 ([email protected])
6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-617

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.

Affected configurations

• emqx cocoamqtt (< 2.2.2)

Related

Weakness · CWE (1)

  • CWE-617 Reachable Assertion weakness

References