CVE-2024-3935: In Eclipse Mosquito, versions from 2.0.0 through 2.0.18, if a Mosquitto broker is configured to create an outg

This month

MEDIUM 6.5UPGRADE

CVE-2024-3935 is a medium-severity flaw (CVSS 6.5) affecting mosquitto. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Eclipse Mosquito, versions from 2.0.0 through 2.0.18, if a Mosquitto broker is configured to create an outgoing bridge connection, and that bridge connection has an incoming topic configured that makes use of topic remapping, then if the remote connection sends a crafted PUBLISH packet to the broker a double free will occur with a subsequent crash of the broker.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.7% (top 45%)
CISA exploited list	No
Weakness	CWE-415
Published	2024-10-30
Last modified	2026-06-17

Publisher (CNA): Eclipse Foundation · Vendor: eclipse

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

Am I affected?

Timeline

2024-10-30 12:15 UTCPublished CVE record published
2026-06-17 07:45 UTCUpdated Record last modified

eclipse mosquitto UPGRADE

Affected: >= 2.0.0 and < 2.0.19

Fixed in: 2.0.19

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. UPGRADE to 2.0.19 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mosquitto

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mosquitto

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison mosquitto sudo apt install mosquitto=<VERSION_BEFORE_2.0.0> sudo apt-mark hold mosquitto

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list mosquitto sudo dnf downgrade mosquitto-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add mosquitto

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-2024-3935?

mosquitto: upgrade to 2.0.19. Exact commands for each OS are on this page.

Is CVE-2024-3935 being exploited?

CVE-2024-3935 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-2024-3935 affect?

CVE-2024-3935 affects mosquitto. Severity is medium (CVSS 6.5). In Eclipse Mosquito, versions from 2.0.0 through 2.0.18, if a Mosquitto broker is configured to create an outgoing bridge connection, and that bridge connection has an incoming topic configured that makes use of topic remapping, then if the

How urgent is CVE-2024-3935?

Priority 41/100. Public exploit reference

Related CVEs

CVE-2024-8376 HIGH 7.5 UPGRADE In Eclipse Mosquitto up to version 2.0.18a, an attacker can achieve memory leaking, segmentation fault or heap
CVE-2024-10525 CRITICAL 9.8 UPGRADE In Eclipse Mosquitto, from version 1.3.2 through 2.0.18, if a malicious broker sends a crafted SUBACK packet w

References

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