CVE-2026-44639

NanoMQ: O(N²) Denial of Service in MQTT v5 Property Parsing

LOW
3.7
CVSS Score
Published: September 18, 2026 at 04:17 PM UTC
Updated: September 18, 2026 at 06:17 PM UTC
1 product affected across 1 vendorNanomq

Using nanomq by nanomq?

Get instant alerts when new vulnerabilities affect nanomq - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
LOW3.7
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's MQTT v5 property decoder in nng/src/supplemental/mqtt/mqtt_codec.c uses property_append() to walk the entire linked list for each property added by decode_buf_properties(). A remote unauthenticated client can supply a PUBLISH or SUBSCRIBE packet containing many User Properties, causing O(N²) linked-list insertion and CPU work that makes the broker unresponsive; repeated packets can sustain the denial of service. This issue is fixed in version 0.24.14.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.24.14
Affected range stops below 0.24.14, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.7LOWGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-407

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card