Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-34608 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Emqx Nanomq. Its CVSS base score is 4.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 29th 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-2026-34608 is an out-of-bounds read vulnerability in the NanoMQ MQTT Broker, an edge messaging platform, affecting versions prior to 0.24.10. The issue resides in the webhook_inproc.c file's hook_work_cb() function, which processes nng messages by passing the message body—obtained via nng_msg_body(msg), a binary buffer lacking a guaranteed null terminator—directly to cJSON_Parse(body). This causes cJSON_Parse to read beyond the allocated buffer boundaries until it encounters a null byte, potentially accessing nng_msg metadata or adjacent heap/stack memory. The flaw is often obscured by nng's allocation padding (extra 32 zero bytes for non-power-of-two sizes under 1024 or non-aligned allocations) but triggers reliably when the JSON payload length is a power-of-two value of 1024 or greater, where no padding is added.
Exploitation requires network access with low attack complexity, no user interaction, and high privileges (PR:H), as indicated by the CVSS 3.1 score of 4.9 (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H). A privileged attacker can send a specially crafted MQTT message with a JSON payload of the specified length to the webhook endpoint, inducing the out-of-bounds read. This results in high-impact availability disruption, such as process crashes or denial of service, with no confidentiality or integrity effects (CWE-125: Out-of-bounds Read, CWE-457: Use of Uninitialized Variable).
The vulnerability has been addressed in NanoMQ version 0.24.10, as detailed in the project's security advisory (GHSA-8p57-jxj9-3qq3), release notes, and patching commit. Security practitioners should upgrade to 0.24.10 or later to mitigate the issue, with the commit available at https://github.com/nanomq/nanomq/commit/9499a4b2c47998a6aadb69238c18b9e6771b1691 and release at https://github.com/nanomq/nanomq/releases/tag/0.24.10.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18464
Vulnerability Data
NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. Prior to version 0.24.10, in NanoMQ's webhook_inproc.c, the hook_work_cb() function processes nng messages by parsing the message body with cJSON_Parse(body). The body is obtained from nng_msg_body(msg), which is a binary…
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buffer without a guaranteed null terminator. This leads to an out-of-bounds read (OOB read) as cJSON_Parse reads until it finds a \0, potentially accessing memory beyond the allocated buffer (e.g., nng_msg metadata or adjacent heap/stack). The issue is often masked by nng's allocation padding (extra 32 bytes of zeros for non-power-of-two sizes <1024 or non-aligned). The overflow is reliably triggered when the JSON payload length is a power-of-two >=1024 (no padding added). This issue has been patched in version 0.24.10.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Documented development standards and tools can enforce initialization requirements in code.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
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.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
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.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.
Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.
Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.