CVE-2026-8686

DoS from MQTT v5.0 Deserialization Fault in core MQTT

Published May 15, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title DoS from MQTT v5.0 Deserialization Fault in core MQTT
First Time appeared Freertos
Freertos coremqtt
Weaknesses CWE-125
CPEs cpe:2.3:a:freertos:coremqtt:5.0.0:*:*:*:*:*:*:*
Vendors & Products Freertos
Freertos coremqtt
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
AMZN
Published
Updated
May 15, 2026, 8:22 PM
Reserved
May 15, 2026, 2:25 PM
Status
Analyzed
Published
May 15, 2026, 7:17 PM
Modified
Oct 25, 2026, 11:10 PM