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Vulnerability record · CVE-2026-21888 · published 11 March 2026

CVE-2026-21888: Emqx nanomq out-of-bounds read vulnerability

Emqx · Nanomq

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() accepts 5-byte varints without bounds checks; reliably triggers OOB read / crash when built with ASan. This affects 0.24.6 and earlier.

7.5 CVSS 3.1 High EPSS 0.30% · top 79.4% CWE-125 · Out-of-bounds read
7.5CVSS 3.1 base score
0.30%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 1 tagged exploit
17 Jun 2026Last modified by NVD

Description

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() accepts 5-byte varints without bounds checks; reliably triggers OOB read / crash when built with ASan. This affects 0.24.6 and earlier.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/nanomq/nanomq/issues/2192 Issue Tracking
https://github.com/nanomq/nanomq/security/advisories/GHSA-cggc-6m7w-j7x5 ExploitVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-21888), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.