What’s Vulnerable › Vulnerabilities

CVE-2026-32134: NanoMQ: NULL Pointer Dereference Crash in tcptran_pipe_peer During Session Restore

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-19 · updated 2026-07-24
• Weakness: CWE-476

Description

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In versions 0.24.10 and below, when NanoMQ handles high-concurrency reconnect traffic using a reconnect-collision payload, the broker can crash due to a NULL pointer dereference during MQTT session resumption for clean_start=0 clients. The transport's p_peer callback (tcptran_pipe_peer()) iterates cpipe->subinfol while copying session metadata from the cached old pipe to the new reconnecting pipe, without checking whether the pointer is NULL. Under a reconnect race, cpipe->subinfol can be freed and set to NULL before session restore invokes this function, resulting in a remote unauthenticated Denial-of-Service (process crash) condition. This issue has been fixed in version 0.24.11.

Affected products

• nanomq: before 0.24.11
• nanomq NanoNNG: before 0.24.11

References

• https://github.com/nanomq/NanoNNG/commit/522ec62e29e60d1122f2aedaa6e702dcf089f7bb
• https://github.com/nanomq/nanomq/issues/2241
• https://github.com/nanomq/nanomq/releases/tag/0.24.11
• https://github.com/nanomq/nanomq/security/advisories/GHSA-q36f-83mh-pcv2
• https://github.com/nanomq/nanomq/issues/2241
• https://github.com/nanomq/nanomq/security/advisories/GHSA-q36f-83mh-pcv2

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