How severe is CVE-2026-22040?

CVE-2026-22040 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-22040 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-22040?

CVE-2026-22040 affects Emqx Nanomq. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-22040?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-22040 have an EU (EUVD) identifier?

Yes. CVE-2026-22040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9497.

When was CVE-2026-22040 published?

CVE-2026-22040 was published on 2026-03-04 and last updated on 2026-06-17.

CVE-2026-22040

CVE-2026-22040 is a medium-severity vulnerability in Emqx Nanomq with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9497
Weakness: CWE-416
Affected product: Emqx Nanomq
Published: 2026-03-04
Last modified: 2026-06-17

Description

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, by generating a combined traffic pattern of high-frequency publishes and rapid reconnect/kick-out using the same ClientID and massive subscribe/unsubscribe jitter, it is possible to reliably trigger heap memory corruption in the Broker process, causing it to exit immediately with SIGABRT due to free(): invalid pointer. As of time of publication, no known patched versions are available.

Frequently asked questions

What is CVE-2026-22040?: NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, by generating a combined traffic pattern of high-frequency publishes and rapid reconnect/kick-out using the same ClientID and massive subscribe/unsubscribe jitter, it is possible to reliably trigger heap memory corruption in the Broker process, causing it to exit immediately with SIGABRT due to free(): invalid pointer. As of time of publication, no known patched versions are available.
How severe is CVE-2026-22040?: CVE-2026-22040 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-22040 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-22040?: CVE-2026-22040 affects Emqx Nanomq. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-22040?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-22040 have an EU (EUVD) identifier?: Yes. CVE-2026-22040 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9497.
When was CVE-2026-22040 published?: CVE-2026-22040 was published on 2026-03-04 and last updated on 2026-06-17.

References

https://github.com/nanomq/nanomq/security/advisories/GHSA-v57q-w88m-424r

Affected products (1)

cpe:2.3:a:emqx:nanomq:*:*:*:*:*:*:*:*

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