Cyber Resilience

CVE-2026-32696

Memory Safety in Emqx Nanomq ≤ 0.24.7

Public PoCMemory Safety
Published
30 March 2026
Modified
13 April 2026
Patch / advisory
CVSS Score v3.1 3.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS Score 0.0040 33th percentile
Risk Priority 28 floored blend · peak EPSS

Summary

CVE-2026-32696 is a low-severity NULL Pointer Dereference (CWE-476) vulnerability in Emqx Nanomq. Its CVSS base score is 3.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 33th 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-15 (Development Process, Standards, and Tools) — 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-2026-32696 is a NULL pointer dereference vulnerability (CWE-476) in the NanoMQ MQTT Broker, an edge messaging platform. It affects version 0.24.6 specifically when HTTP authentication (auth.http_auth) is enabled and configuration parameters use placeholders like %u for username and %P for password. During the HTTP request construction in auth_http.c:set_data(), an MQTT CONNECT packet without username or password triggers a strlen() call on a NULL pointer, resulting in a SIGSEGV crash.

A remote, unauthenticated attacker can exploit this by sending an MQTT CONNECT packet lacking credentials to the broker under the specified configuration. This leads to a denial-of-service condition via broker crash. The CVSS v3.1 base score of 3.1 (AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L) reflects low severity, with high attack complexity and required user interaction.

The issue is addressed in NanoMQ version 0.24.7. Mitigation involves upgrading to the patched release, as detailed in the GitHub security advisory (GHSA-77f4-wvq8-mp3p), release notes, associated pull request (#1394), and commit (c20aa27e5290bb480a5315099952480d35f37a8b).

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In NanoMQ version 0.24.6, after enabling auth.http_auth (HTTP authentication), when a client connects to the broker using MQTT CONNECT without providing username/password, and the configuration params uses the placeholders %u…

more

/ %P (e.g., username="%u", password="%P"), the HTTP request construction phase enters auth_http.c:set_data(). This results in calling strlen() on a NULL pointer, causing a SIGSEGV crash. This crash can be triggered remotely, resulting in a denial of service. This issue has been patched in version 0.24.7.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
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.
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-29996Same product: Emqx Nanomq
CVE-2025-68699Same product: Emqx Nanomq
CVE-2024-31041Same product: Emqx Nanomq
CVE-2024-42649Same product: Emqx Nanomq
CVE-2024-42651Same product: Emqx Nanomq
CVE-2026-36590Same product: Emqx Nanomq
CVE-2024-48077Same product: Emqx Nanomq
CVE-2023-33656Same product: Emqx Nanomq
CVE-2023-33660Same product: Emqx Nanomq
CVE-2026-32135Same product: Emqx Nanomq

Affected Assets

emqx
nanomq
≤ 0.24.7

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

Engineering principles can mandate defensive coding such as explicit null checks before dereference.

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 (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

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.

finds

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References