CVE-2026-25627
Prior to version 0.24.8, NanoMQ’s MQTT-over-WebSocket transport can be crashed by sending an MQTT packet with a deliberately large Remaining Length in the fixed header while providing a much shorter actual payload.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). 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 0.24.8, NanoMQ’s MQTT-over-WebSocket transport can be crashed by sending an MQTT packet with a deliberately large Remaining Length in the fixed header while providing a much shorter actual payload. The code path copies Remaining Length bytes without verifying that the current receive buffer contains that many bytes, resulting in an out-of-bounds read (ASAN reports OOB / crash). This is remotely triggerable over the WebSocket listener. This issue has been patched in version 0.24.8.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.47% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- emqx/nanomq
- Source
- security-advisories@github.com
References
- https://github.com/nanomq/NanoNNG/commit/e80b30bad6d855593a68d18f2785bfaca6faf09ePatch
- https://github.com/nanomq/NanoNNG/pull/1405Issue Tracking, Patch
- https://github.com/nanomq/nanomq/releases/tag/0.24.8Release Notes
- https://github.com/nanomq/nanomq/security/advisories/GHSA-w4rh-v3h2-j29xExploit, Vendor Advisory
- https://github.com/nanomq/nanomq/security/advisories/GHSA-w4rh-v3h2-j29xExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.