What is CVE-2026-21888?

CVE-2026-21888 is a high-severity vulnerability in Nanomq, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-03-11.

How severe is CVE-2026-21888?

High severity. CVSS v3 base score is 7.5 out of 10.

Out-of-bounds Read in Nanomq

CVE-2026-21888

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 A…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (26.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Nanomq — versions <= 0.24.6

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

https://github.com/nanomq/nanomq/security/advisories/GHSA-cggc-6m7w-j7x5 (x_refsource_CONFIRM)
https://github.com/nanomq/nanomq/issues/2192 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-21888?: CVE-2026-21888 is a high-severity vulnerability in Nanomq, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-03-11.
How severe is CVE-2026-21888?: High severity. CVSS v3 base score is 7.5 out of 10.