CVE-2026-8686

HIGH

DoS from MQTT v5.0 Deserialization Fault in core MQTT

Title source: cna
STIX 2.1

Description

Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet. To remediate this issue, users should upgrade to v5.0.1.

Scores

CVSS v3 7.5
EPSS 0.0039
EPSS Percentile 30.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-125
Status published
Products (2)
freertos/coremqtt 5.0.0
FreeRTOS/coreMQTT 5.0.0
Published May 15, 2026
Tracked Since May 16, 2026