PT-2026-29743 · Cocoamqtt · Cocoamqtt

T5Uki · Published 2026-04-02 · Updated 2026-04-03 · CVE-2026-30867

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions CocoaMQTT versions prior to 2.2.2

Description A flaw exists in the packet parsing logic of CocoaMQTT that allows a remote attacker, or a compromised MQTT broker, to crash iOS/macOS/tvOS applications. Publishing a 4-byte malformed payload to a shared topic with the RETAIN flag set to true causes the MQTT broker to persist the payload. When a vulnerable client connects and subscribes to that topic, the broker sends the malformed packet, resulting in an application crash. This creates a persistent denial-of-service condition until the retained message is removed from the broker database.

Recommendations Update CocoaMQTT to version 2.2.2 or later.

Fix

Assertion Failure

Weakness Enumeration

CWE-617

Related Identifiers

CVE-2026-30867

GHSA-R3FR-7M74-Q7G2

Affected Products

Cocoamqtt

References · 8

• https://github.com/emqx/CocoaMQTT/pull/659 · Patch
• https://github.com/emqx/CocoaMQTT/security/advisories/GHSA-r3fr-7m74-q7g2 · Vendor Advisory
• https://github.com/emqx/CocoaMQTT/commit/010bca6f61b97d726252f61641d331a2bf82b338 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-30867 · Security Note
• https://osv.dev/vulnerability/GHSA-r3fr-7m74-q7g2 · Vendor Advisory
• https://github.com/emqx/CocoaMQTT/releases/tag/2.2.2 · Note
• https://github.com/emqx/CocoaMQTT · Note
• https://twitter.com/CVEnew/status/2039744344534442058 · Twitter Post