CVE-2026-8686

EUVD-2026-30581
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 30%
Affected Products (NVD)
VendorProductVersion
freertoscoremqtt
5.0.0
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://aws.amazon.com/security/security-bulletins/2026-032-aws/
https://github.com/FreeRTOS/coreMQTT/releases/tag/v5.0.1
https://github.com/FreeRTOS/coreMQTT/security/advisories/GHSA-6qh9-r6jp-2wxc