CVE-2024-10525: In Eclipse Mosquitto, from version 1.3.2 through 2.0.18, if a malicious broker sends a crafted SUBACK packet w

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2024-10525 is a critical-severity flaw (CVSS 9.8) affecting mosquitto. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Eclipse Mosquitto, from version 1.3.2 through 2.0.18, if a malicious broker sends a crafted SUBACK packet with no reason codes, a client using libmosquitto may make out of bounds memory access when acting in its on_subscribe callback. This affects the mosquitto_sub and mosquitto_rr clients.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	59.2% (top 1%)
CISA exploited list	No
Weakness	CWE-122, CWE-787
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 06:55 UTCUpdated Record last modified

eclipse mosquitto UPGRADE

Affected: >= 1.3.2 and < 2.0.19

Fixed in: 2.0.19

Safe to downgrade to: a release before 1.3.2

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 1.3.2 (Debian / Ubuntu)

apt-cache madison mosquitto sudo apt install mosquitto=<VERSION_BEFORE_1.3.2> 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_1.3.2> 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.

Exact fixes by distribution

Fedora 46 · byobu · FIXED · 7.23-1.fc46 · FEDORA-2026-08f2b53446 · source

sudo dnf upgrade --advisory=FEDORA-2026-08f2b53446

Ubuntu 20.04 · mosquitto · FIXED · 1.6.9-1ubuntu0.1~esm2

sudo apt update && sudo apt install --only-upgrade mosquitto dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mosquitto)" ge "1.6.9-1ubuntu0.1~esm2" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · mosquitto · FIXED · 2.0.11-1ubuntu1.2

sudo apt update && sudo apt install --only-upgrade mosquitto dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mosquitto)" ge "2.0.11-1ubuntu1.2" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · mosquitto · FIXED · 2.0.18-1ubuntu0.1~esm1

sudo apt update && sudo apt install --only-upgrade mosquitto dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mosquitto)" ge "2.0.18-1ubuntu0.1~esm1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.04 · mosquitto · NOT AFFECTED

Ubuntu 25.10 · mosquitto · NOT AFFECTED

Debian 12 · mosquitto · FIXED · 2.0.11-1.2+deb12u2

sudo apt update && sudo apt install --only-upgrade mosquitto dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mosquitto)" ge "2.0.11-1.2+deb12u2" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · mosquitto · FIXED · 2.0.20-1

sudo apt update && sudo apt install --only-upgrade mosquitto dpkg --compare-versions "$(dpkg-query -W -f='${Version}' mosquitto)" ge "2.0.20-1" && echo PATCHED || echo STILL-VULNERABLE

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-2024-10525?

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

Is CVE-2024-10525 being exploited?

CVE-2024-10525 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-2024-10525 affect?

CVE-2024-10525 affects mosquitto. Severity is critical (CVSS 9.8). In Eclipse Mosquitto, from version 1.3.2 through 2.0.18, if a malicious broker sends a crafted SUBACK packet with no reason codes, a client using libmosquitto may make out of bounds memory access when acting in its on_subscribe callback. Th

How urgent is CVE-2024-10525?

Priority 69/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

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-2024-3935 MEDIUM 6.5 UPGRADE In Eclipse Mosquito, versions from 2.0.0 through 2.0.18, if a Mosquitto broker is configured to create an outg

References

← Back to latest CVEs