CVE-2026-34608

HIGHCVSS 8.2/10EPSS 0.36%

Last modified

CVE-2026-34608 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. 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). EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

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 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.

Metrics

CVSS 3.1
8.2/10

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

EPSS Probability
0.36%

27.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
EmqxNanomq< 0.24.10

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-34608?
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 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.
How severe is CVE-2026-34608?
CVE-2026-34608 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.
How do I fix CVE-2026-34608?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-34608?

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Source: NVD / NIST