Cyber Resilience

CVE-2025-10543

Eclipse Paho Mqtt ≤ 1.5.0

Published
02 December 2025
Modified
16 January 2026
Patch / advisory
View advisory
CVSS Score v4 6.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0022 13th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2025-10543 is a medium-severity Numeric Truncation Error (CWE-197) vulnerability in Eclipse Paho Mqtt. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In Eclipse Paho Go MQTT v3.1 library (paho.mqtt.golang) versions <=1.5.0 UTF-8 encoded strings, passed into the library, may be incorrectly encoded if their length exceeds 65535 bytes. This may lead to unexpected content in packets sent to the server (for…

more

example, part of an MQTT topic may leak into the message body in a PUBLISH packet). The issue arises because the length of the data passed in was converted from an int64/int32 (depending upon CPU) to an int16 without checks for overflows. The int16 length was then written, followed by the data (e.g. topic). This meant that when the data (e.g. topic) was over 65535 bytes then the amount of data written exceeds what the length field indicates. This could lead to a corrupt packet, or mean that the excess data leaks into another field (e.g. topic leaks into message body).

CWE(s)
CWE-197CWE-681

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-2259Same vendor: Eclipse
CVE-2025-55078Same vendor: Eclipse
CVE-2023-48694Same vendor: Eclipse
CVE-2025-55080Same vendor: Eclipse
CVE-2024-2452Same vendor: Eclipse
CVE-2025-55096Same vendor: Eclipse
CVE-2025-4447Same vendor: Eclipse
CVE-2026-9158Same vendor: Eclipse
CVE-2026-1188Same vendor: Eclipse
CVE-2024-10838Same vendor: Eclipse

Affected Assets

eclipse
paho mqtt
≤ 1.5.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover truncation errors through static analysis, dynamic testing, or code review.

SA-15 Development Process, Standards, and Tools partial match

Documented development standards and tools can mandate use of safe arithmetic libraries or explicit checks against truncation.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require safe type conversions and avoidance of narrowing casts that cause truncation.

SI-10 Information Input Validation partial match

Input validation directly stops malformed or out-of-range numeric values from reaching conversion logic.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent truncation errors via reviews, static analysis, and safe type handling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect truncation bugs through static analysis and fuzzing.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates practices that can catch numeric truncation during design and code review.

A.8.26 Application security requirements partial match
degrades

Application security requirements can specify safe numeric handling and data-type constraints.

A.8.27 Secure system architecture and engineering principles partial match
degrades

Secure architecture principles include choosing appropriate data types and avoiding unsafe casts.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit unsafe narrowing conversions and truncation.

References