CVE-2026-8686

DoS from MQTT v5.0 Deserialization Fault in core MQTT

CVSS 8.7 HIGHEPSS 0.4%CWE-125

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 8.7EPSS 0.4%KEV nãoPoC —Nuclei —Metasploit —Patch referenciado

Lifecycle

15 May 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected products

FreeRTOS · coreMQTT

Want to know if your infrastructure is exposed to this?

Talk to TrueHacking →

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