CVE-2026-30867

CocoaMQTT prior to v2.2.2 is vulnerable to a Denial of Service via a malformed 4-byte PUBLISH payload with the RETAIN flag set. A malicious broker or attacker can cause a vulnerable iOS/macOS/tvOS client to crash when it subscribes to the affected topic, leading to a persistent DoS until the reta...

CVE-2026-30867 CocoaMQTT: Denial of Service via Reachable Assertion in `PUBLISH` Packet Parsing

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...