What’s Vulnerable › Vulnerabilities

CVE-2019-11779

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-09-19 · updated 2026-06-17
• Weakness: CWE-754

Description

In Eclipse Mosquitto 1.5.0 to 1.6.5 inclusive, if a malicious MQTT client sends a SUBSCRIBE packet containing a topic that consists of approximately 65400 or more '/' characters, i.e. the topic hierarchy separator, then a stack overflow will occur.

Affected products

• Canonical Ubuntu Linux: 19.04
• Debian Linux: 8.0, 10.0
• The Eclipse Foundation Eclipse Mosquitto: from 1.5 before 1.5.9; from 1.6 before 1.6.6 — fixed in 1.5.9, 1.6.6
• Fedoraproject Fedora: 29, 30, 31
• openSUSE Backports Sle: 15.0-sp1
• openSUSE Leap: 15.1

How to fix

Upgrade to a fixed version: The Eclipse Foundation Eclipse Mosquitto 1.5.9, 1.6.6. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00077.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00008.html
• https://bugs.eclipse.org/bugs/show_bug.cgi?id=551160
• https://lists.debian.org/debian-lts-announce/2019/10/msg00035.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D4WMHIM64Q35NGTR6R3ILZUL4MA4ANB5/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HFWQBNFTAVHPUYNGYO2TCPF5PCSWC2Z7/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JWNVTFA2CKXERXRYPYE2YFTZP4GNBGYY/
• https://seclists.org/bugtraq/2019/Nov/25
• https://usn.ubuntu.com/4137-1/
• https://www.debian.org/security/2019/dsa-4570
• http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00077.html
• http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00008.html

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