CVE-2025-68699: NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform

Routine

MEDIUM 6.5DOWNGRADE

CVE-2025-68699 is a medium-severity flaw (CVSS 6.5) affecting nanomq. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, NanoMQ has a protocol parsing / forwarding inconsistency when handling shared subscriptions ($share/). A malformed SUBSCRIBE topic such as $share/ab (missing the second /) is not strictly validated during the subscription stage, so the invalid Topic Filter is stored into the subscription table. Later, when any PUBLISH matches this subscription, the broker sen

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-02-04
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: emqx

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-04 20:16 UTCPublished CVE record published
2026-06-17 09:59 UTCUpdated Record last modified

emqx nanomq DOWNGRADE

Affected: 0.24.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.24.6

1. Check installed version

apt-cache policy nanomq || rpm -q nanomq || nanomq --version

2. No fixed release: DOWNGRADE to a release before 0.24.6 (Debian / Ubuntu)

apt-cache madison nanomq sudo apt install nanomq=<VERSION_BEFORE_0.24.6> sudo apt-mark hold nanomq

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nanomq sudo dnf downgrade nanomq-<VERSION_BEFORE_0.24.6> sudo dnf versionlock add nanomq

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-68699?

nanomq: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-68699 being exploited?

CVE-2025-68699 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-68699 affect?

CVE-2025-68699 affects nanomq. Severity is medium (CVSS 6.5). NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform. In version 0.24.6, NanoMQ has a protocol parsing / forwarding inconsistency when handling shared subscriptions ($share/). A malformed SUBSCRIBE topic such as $share/ab (m

How urgent is CVE-2025-68699?

Priority 34/100. Public exploit reference

Related CVEs

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CVE-2026-34608 MEDIUM 4.9 UPGRADE NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform
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CVE-2026-25627 MEDIUM 6.5 UPGRADE NanoMQ MQTT Broker (NanoMQ) is an all-around Edge Messaging Platform
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References

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