CVE-2026-32135

HighPublic PoC

Published: 20 April 2026

Published

20 April 2026

Modified

22 April 2026

KEV Added

—

Patch

—

CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Score 0.0026 49.0th percentile

Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-32135 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Emqx Nanomq. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 49.0th 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 are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly remediates the heap buffer overflow by requiring timely patching to NanoMQ version 0.24.11 or later.

SI-16 Memory Protection good match

prevent

Provides memory protection mechanisms such as ASLR and DEP to prevent successful exploitation of the heap buffer overflow.

SI-10 Information Input Validation partial match

prevent

Enforces validation of HTTP URI parameters to reject crafted requests that could trigger the off-by-one allocation error.

MITRE ATT&CK Enterprise TechniquesAI

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 →

T1499.004 Application or System Exploitation Impact

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.

attack.mitre.org →

Why these techniques?

Remote unauthenticated heap buffer overflow in public NanoMQ REST API (uri_param_parse) directly enables T1190 exploitation of a public-facing application; the resulting broker crash maps to T1499.004 Application or System Exploitation for endpoint DoS.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Versions prior to 0.24.11 have a remotely triggerable heap buffer overflow in the `uri_param_parse` function of NanoMQ's REST API. The vulnerability occurs due to an off-by-one error when allocating memory…

for query parameter keys and values, allowing an attacker to write a null byte beyond the allocated buffer. This can be triggered via a crafted HTTP request. Version 0.24.11 patches the issue.

Deeper analysisAI

CVE-2026-32135 is a heap buffer overflow vulnerability in the `uri_param_parse` function of NanoMQ's REST API. NanoMQ, an all-around Edge Messaging Platform and MQTT Broker, is affected in versions prior to 0.24.11. The issue stems from an off-by-one error during memory allocation for query parameter keys and values, which allows an attacker to write a null byte beyond the allocated buffer boundaries. This vulnerability is classified under CWE-122 (Heap-based Buffer Overflow) with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

The vulnerability can be exploited remotely by any unauthenticated attacker with network access to the NanoMQ REST API endpoint. By sending a specially crafted HTTP request, the attacker triggers the off-by-one error, leading to a heap buffer overflow. This results in high-impact availability disruption, such as broker crashes or denial of service, without affecting confidentiality or integrity.

Mitigation is available in NanoMQ version 0.24.11, which patches the allocation logic in the `uri_param_parse` function. Security advisories and the fixing commit are detailed in the NanoMQ GitHub security advisory (GHSA-6w96-9qw7-m599), issue tracker (#2247), and the specific patch commit (69a97b3b39cc218f044f1c8896f4d3d8757bb394). Practitioners should upgrade to the patched version and review exposed REST API access.