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CVE-2023-0809

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that...

5.8 MediumFix available

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
Low

Exploit likelihood

0.71%Up 0.7 points since Oct 3, 2023
90%50%10%1%

What each source reports

CVE List Score used 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
CVE-2023-0809
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness
CWE-789
Updated
2026-11-02
EUVDEUVD-2023-12814 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
EUVD-2023-12814
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Updated
2026-11-03
GitHub AdvisoriesGHSA-v9xr-r3xx-x9gc 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that...

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
GHSA-v9xr-r3xx-x9gc
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness
CWE-770, CWE-789
Updated
2026-11-02
NVD 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
CVE-2023-0809
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness
CWE-789, CWE-770
Updated
2026-11-02
OSVALPINE-CVE-2023-0809 5.3

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
ALPINE-CVE-2023-0809
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVBELL-CVE-2023-0809 5.3

CVE-2023-0809 does not affect BellSoft software

Record
BELL-CVE-2023-0809
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
Show 10 moreShow less
OSV 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
CVE-2023-0809
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness
CWE-789
Updated
2026-11-02
OSVDEBIAN-CVE-2023-0809 5.3

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
DEBIAN-CVE-2023-0809
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVOESA-2023-1716 5.3

mosquitto security update

Mosquitto is an open source message broker that implements the MQ Telemetry Transport protocol version 3.1 and 3.1.1 MQTT provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for "machine to machine" messaging such as with low power sensors or mobile devices such as phones, embedded computers or micro-controllers like the Arduino.

Security Fix(es):

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.(CVE-2023-0809)

Record
OESA-2023-1716
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVOESA-2023-1717 5.3

mosquitto security update

Mosquitto is an open source message broker that implements the MQ Telemetry Transport protocol version 3.1 and 3.1.1 MQTT provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for "machine to machine" messaging such as with low power sensors or mobile devices such as phones, embedded computers or micro-controllers like the Arduino.

Security Fix(es):

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.(CVE-2023-0809)

Record
OESA-2023-1717
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVOESA-2023-1718 5.3

mosquitto security update

Mosquitto is an open source message broker that implements the MQ Telemetry Transport protocol version 3.1 and 3.1.1 MQTT provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for "machine to machine" messaging such as with low power sensors or mobile devices such as phones, embedded computers or micro-controllers like the Arduino.

Security Fix(es):

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.(CVE-2023-0809)

Record
OESA-2023-1718
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVRHSA-2024:0797 8.1

Red Hat Security Advisory: Satellite 6.14.2 Async Security Update

Record
RHSA-2024:0797
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated
2026-11-02
OSVRHSA-2024:1061 7.5

Red Hat Security Advisory: Red Hat Satellite 6 security and bug fix update

Record
RHSA-2024:1061
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVUBUNTU-CVE-2023-0809 5.8

In Mosquitto before 2.0.16, excessive memory is allocated based on malicious initial packets that are not CONNECT packets.

Record
UBUNTU-CVE-2023-0809
CVSS 3.1
5.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Updated
2026-11-02
OSVopenSUSE-SU-2024:13546-1 No score

libmosquitto1-2.0.18-1.1 on GA media

These are all security issues fixed in the libmosquitto1-2.0.18-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:13546-1
Updated
2026-11-02
OSVUSN-6492-1 No score

mosquitto vulnerabilities

Kathrin Kleinhammer discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-34431)

Zhanxiang Song discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause an authorisation bypass. This issue only affected Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2021-34434)

Zhanxiang Song, Bin Yuan, DeQing Zou, and Hai Jin discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2021-41039)

Zhengjie Du discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2023-0809)

It was discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2023-3592)

Mischa Bachmann discovered that Mosquitto incorrectly handled certain inputs. If a user or an automated system were provided with a specially crafted input, a remote attacker could possibly use this issue to cause a denial of service. This issue was only fixed in Ubuntu 22.04 LTS and Ubuntu 23.04. (CVE-2023-28366)

Record
USN-6492-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
mosquitto
Alpine:v3.18
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.19
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.20
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.21
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.22
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.23
before 2.0.16-r0
2.0.16-r0
mosquitto
Alpine:v3.24
before 2.0.16-r0
2.0.16-r0
mosquitto
Debian:12
before 2.0.11-1.2+deb12u1, plus listed versions
2.0.11-1.2
2.0.11-1.2+deb12u1
mosquitto
Debian:13
before 2.0.17-1
2.0.17-1
mosquitto
Debian:14
before 2.0.17-1
2.0.17-1
Show 49 moreShow less
Affected packages
PackageAffectedFixed
mosquitto
Debian:11
From an advisory covering 4 CVEs
before 2.0.11-1+deb11u1, plus listed versions
2.0.11-1
2.0.11-1+deb11u1
mosquitto
Debian:12
From an advisory covering 4 CVEs
before 2.0.11-1.2+deb12u1, plus listed versions
2.0.11-1.2
2.0.11-1.2+deb12u1
mosquitto
openEuler:22.03-LTS-SP1
before 2.0.16-1.oe2203sp1
2.0.16-1.oe2203sp1
mosquitto
openEuler:22.03-LTS-SP2
before 2.0.16-1.oe2203sp2
2.0.16-1.oe2203sp2
mosquitto
openEuler:22.03-LTS
before 2.0.16-1.oe2203
2.0.16-1.oe2203
mosquitto
Red Hat:satellite_capsule:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debuginfo
Red Hat:satellite_capsule:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debugsource
Red Hat:satellite_capsule:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debuginfo
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debugsource
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
rubygem-grpc
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:1.58.0-1.el8sat
0:1.58.0-1.el8sat
puppetserver
Red Hat:satellite_capsule:6.14::el8
From an advisory covering 10 CVEs
before 0:7.14.0-1.el8sat
0:7.14.0-1.el8sat
puppetserver
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:7.14.0-1.el8sat
0:7.14.0-1.el8sat
rubygem-sidekiq
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:6.5.12-1.el8sat
0:6.5.12-1.el8sat
candlepin
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:4.3.11-1.el8sat
0:4.3.11-1.el8sat
candlepin-selinux
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:4.3.11-1.el8sat
0:4.3.11-1.el8sat
puppet-agent
Red Hat:satellite_capsule:6.14::el8
From an advisory covering 10 CVEs
before 0:7.27.0-1.el8sat
0:7.27.0-1.el8sat
puppet-agent
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:7.27.0-1.el8sat
0:7.27.0-1.el8sat
rubygem-puma
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:6.3.1-1.el8sat
0:6.3.1-1.el8sat
rubygem-puma-debuginfo
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:6.3.1-1.el8sat
0:6.3.1-1.el8sat
rubygem-puma-debugsource
Red Hat:satellite:6.14::el8
From an advisory covering 10 CVEs
before 0:6.3.1-1.el8sat
0:6.3.1-1.el8sat
foreman
Red Hat:satellite_capsule:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman
Red Hat:satellite_utils:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
mosquitto
Red Hat:satellite_capsule:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debuginfo
Red Hat:satellite_capsule:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debugsource
Red Hat:satellite_capsule:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debuginfo
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
mosquitto-debugsource
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:2.0.17-1.el8sat
0:2.0.17-1.el8sat
foreman-debug
Red Hat:satellite_capsule:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-cli
Red Hat:satellite_utils:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-cli
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-debug
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-dynflow-sidekiq
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-ec2
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-journald
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-libvirt
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-openstack
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-ovirt
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-postgresql
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-service
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-telemetry
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
foreman-vmware
Red Hat:satellite:6.13::el8
From an advisory covering 5 CVEs
before 0:3.5.1.24-1.el8sat
0:3.5.1.24-1.el8sat
mosquitto
Ubuntu:Pro:20.04:LTS
before 1.6.9-1ubuntu0.1~esm1, plus listed versions
1.6.6-11.6.7-11.6.8-11.6.8-21.6.9-1~build11.6.9-1
1.6.9-1ubuntu0.1~esm1
mosquitto
Ubuntu:22.04:LTS
before 2.0.11-1ubuntu1.1, plus listed versions
2.0.11-12.0.11-1build12.0.11-1ubuntu1
2.0.11-1ubuntu1.1
mosquitto
Ubuntu:Pro:20.04:LTS
From an advisory covering 6 CVEs
before 1.6.9-1ubuntu0.1~esm1, plus listed versions
1.6.6-11.6.7-11.6.8-11.6.8-21.6.9-1~build11.6.9-1
1.6.9-1ubuntu0.1~esm1
mosquitto
Ubuntu:22.04:LTS
From an advisory covering 6 CVEs
before 2.0.11-1ubuntu1.1, plus listed versions
2.0.11-12.0.11-1build12.0.11-1ubuntu1
2.0.11-1ubuntu1.1

History

History
RecordedChangedSources
affected, facts
aliases, productsEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2023-0809 is a medium vulnerability (CVSS 5.8) in Eclipse Mosquitto, published August 31, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.71%, the 53rd percentile. Fixed in mosquitto 2.0.16-r0.

References

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