Cyber Resilience

CVE-2026-25627

Memory Safety in Emqx Nanomq ≤ 0.24.8

Public PoCMemory Safety
Published
30 March 2026
Modified
02 April 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0047 39th percentile
Risk Priority 50 floored blend · peak EPSS

Summary

CVE-2026-25627 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Emqx Nanomq. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 39th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-25627 is an out-of-bounds read vulnerability in the MQTT-over-WebSocket transport of NanoMQ, an all-around Edge Messaging Platform and MQTT Broker. In versions prior to 0.24.8, the broker can be crashed by an MQTT packet with a deliberately large Remaining Length value in the fixed header paired with a much shorter actual payload. The affected code path copies the specified number of Remaining Length bytes from the receive buffer without first verifying that the buffer contains sufficient data, leading to an out-of-bounds read and crash, as reported by ASAN.

The vulnerability is remotely exploitable over the WebSocket listener with low attack complexity and no user interaction required. Exploitation requires low privileges (PR:L per CVSS 3.1 score of 6.5: AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), allowing an attacker with such access to trigger a denial-of-service by crashing the NanoMQ broker instance. There is no impact on confidentiality or integrity.

The issue has been addressed in NanoMQ version 0.24.8, as detailed in the project's release notes, security advisories (GHSA-w4rh-v3h2-j29x), and the patching commit (e80b30bad6d855593a68d18f2785bfaca6faf09e) merged via pull request #1405. Security practitioners should upgrade to the fixed version to mitigate this CWE-125 vulnerability.

EU & UK References

Vulnerability Data

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Prior to version 0.24.8, NanoMQ’s MQTT-over-WebSocket transport can be crashed by sending an MQTT packet with a deliberately large Remaining Length in the fixed header while providing a much shorter…

more

actual payload. The code path copies Remaining Length bytes without verifying that the current receive buffer contains that many bytes, resulting in an out-of-bounds read (ASAN reports OOB / crash). This is remotely triggerable over the WebSocket listener. This issue has been patched in version 0.24.8.

CWE(s)
CWE-125

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 →
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
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-2024-44460Same product: Emqx Nanomq
CVE-2024-42646Same product: Emqx Nanomq
CVE-2026-21888Same product: Emqx Nanomq
CVE-2026-34608Same product: Emqx Nanomq
CVE-2023-33660Same product: Emqx Nanomq
CVE-2023-34488Same product: Emqx Nanomq
CVE-2023-33658Same product: Emqx Nanomq
CVE-2023-29995Same product: Emqx Nanomq
CVE-2024-42648Same product: Emqx Nanomq
CVE-2023-29994Same product: Emqx Nanomq

Affected Assets

emqx
nanomq
≤ 0.24.8

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

SC-39 Process Isolation partial match

Process isolation confines the effects of an out-of-bounds read to the compromised process.

SI-10 Information Input Validation partial match

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

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-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

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 in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

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

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References