CVE-2024-36856Public exploitNetwork attack vector

Daemon crash via unbounded persistent sessions

Published Jun 12, 2024 · Updated Apr 3, 2026

Denial of service in RMQTT Broker 0.4.0 allows remote attackers to exhaust memory and crash the daemon through long-lived MQTT sessions. The MQTT 5 handshake copies the client-supplied session expiry interval into broker state instead of applying the server fitter's configured expiry, allowing attacker-created publish/subscribe sessions to persist. Unauthenticated network access to the MQTT listener is sufficient; enough maintained sessions consume memory until the broker crashes.

CVSS severity7.5
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in RMQTT Broker 0.4.0 allows remote attackers to exhaust memory and crash the daemon through long-lived MQTT sessions. The MQTT 5 handshake copies the client-supplied session expiry interval into broker state instead of applying the server fitter's configured expiry, allowing attacker-created publish/subscribe sessions to persist. Unauthenticated network access to the MQTT listener is sufficient; enough maintained sessions consume memory until the broker crashes.

The record

CVE
CVE-2024-36856
Published
Jun 12, 2024
Updated
Apr 3, 2026
Vendor
RMQTT
Product
RMQTT
Classifications
CWE-404, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RMQTT · RMQTTversion=0.4.0

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
T1499.003Application Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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