CVE-2026-34608
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).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125, CWE-457
- Affected
- emqx/nanomq
- Source
- security-advisories@github.com
References
- https://github.com/nanomq/nanomq/commit/9499a4b2c47998a6aadb69238c18b9e6771b1691Patch
- https://github.com/nanomq/nanomq/releases/tag/0.24.10Product, Release Notes
- https://github.com/nanomq/nanomq/security/advisories/GHSA-8p57-jxj9-3qq3Exploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.