CVE-2025-68699
NanoMQ $share/ Subscription Validation and Forwarding Parsing Inconsistency: NULL Pointer Increment Causes Crash
Description
NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, NanoMQ has a protocol parsing / forwarding inconsistency when handling shared subscriptions ($share/). A malformed SUBSCRIBE topic such as $share/ab (missing the second /) is not strictly validated during the subscription stage, so the invalid Topic Filter is stored into the subscription table. Later, when any PUBLISH matches this subscription, the broker send path (nmq_pipe_send_start_v4/v5) performs a second $share/ parsing using strchr() and increments the returned pointer without NULL checks. If the second strchr() returns NULL, sub_topic++ turns the pointer into an invalid address (e.g. 0x1). This invalid pointer is then passed into topic_filtern(), which triggers strlen() and crashes with SIGSEGV. The crash is stable and remotely triggerable. This issue has been patched in version 0.24.7.
INFO
Published Date :
Feb. 4, 2026, 8:16 p.m.
Last Modified :
Feb. 4, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-68699
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update NanoMQ MQTT Broker to version 0.24.7.
- Apply vendor patches if updating is not possible.
- Validate subscription topic filters strictly.
- Ensure topic parsing handles NULL pointers correctly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-68699.
| URL | Resource |
|---|---|
| https://github.com/nanomq/nanomq/commit/89d68d678e7f841ae7baa45cba8d9bc7ddc9ef4b | |
| https://github.com/nanomq/nanomq/security/advisories/GHSA-qv5f-c6v2-2f8h |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-68699 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-68699
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-68699 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-68699 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Feb. 04, 2026
Action Type Old Value New Value Added Description NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, NanoMQ has a protocol parsing / forwarding inconsistency when handling shared subscriptions ($share/). A malformed SUBSCRIBE topic such as $share/ab (missing the second /) is not strictly validated during the subscription stage, so the invalid Topic Filter is stored into the subscription table. Later, when any PUBLISH matches this subscription, the broker send path (nmq_pipe_send_start_v4/v5) performs a second $share/ parsing using strchr() and increments the returned pointer without NULL checks. If the second strchr() returns NULL, sub_topic++ turns the pointer into an invalid address (e.g. 0x1). This invalid pointer is then passed into topic_filtern(), which triggers strlen() and crashes with SIGSEGV. The crash is stable and remotely triggerable. This issue has been patched in version 0.24.7. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CWE CWE-476 Added Reference https://github.com/nanomq/nanomq/commit/89d68d678e7f841ae7baa45cba8d9bc7ddc9ef4b Added Reference https://github.com/nanomq/nanomq/security/advisories/GHSA-qv5f-c6v2-2f8h