CVE-2025-63235Public exploitNetwork attack vector

Unauthenticated service crash via retained MQTT sessions

Published Aug 7, 2026 · Updated Aug 7, 2026

Resource exhaustion in codepr sol commit 373d848 allows remote attackers to crash the MQTT broker via malformed CONNECT packets. Invalid or duplicate CONNECT handling leaves TCP sessions open and retains client buffers, memory, and file descriptors without cleanup or an idle timeout. No authentication is required for duplicate CONNECT attempts; sustained half-open sessions exhaust host resources and terminate the broker process.

CVSS severity7.5
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in codepr sol commit 373d848 allows remote attackers to crash the MQTT broker via malformed CONNECT packets. Invalid or duplicate CONNECT handling leaves TCP sessions open and retains client buffers, memory, and file descriptors without cleanup or an idle timeout. No authentication is required for duplicate CONNECT attempts; sustained half-open sessions exhaust host resources and terminate the broker process.

The record

CVE
CVE-2025-63235
Published
Aug 7, 2026
Updated
Aug 7, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 7, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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