Improper Handling of Exceptional Conditions and Origin Validation Error in Eclipse Paho Java client library

published 2019-09-11 7 y ago modified 2026-06-17 4 mo ago also GHSA-63qc-p2x4-9fgf , EUVD-2019-0656

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

In the Eclipse Paho Java client library version 1.2.0, when connecting to an MQTT server using TLS and setting a host name verifier, the result of that verification is not checked. This could allow one MQTT server to impersonate another and provide the client library with incorrect information.

Patch / fix

fixed in 1

maven org.eclipse.paho:org.eclipse.paho.client.mqttv3 1.2.1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-11777 updated 2026-05-14 cvss 7.4

org.eclipse.paho.client.mqttv3: Improper hostname validation in the MQTT library

Red Hat JBoss Fuse 6 org.eclipse.paho.client.mqttv3
affected: no fix planned “Out of support scope”
Red Hat Fuse 7.8.0
fixed: vendor fix RHSA-2020:5568

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N
GitHub	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	org.eclipse.paho:org.eclipse.paho.client.mqttv3	<1.2.1	1.2.1

Affected products

The Eclipse Foundation Eclipse Paho

Classification

Weakness

CWE-346 Origin Validation Error
CWE-755 Improper Handling of Exceptional Conditions

References

bugs.eclipse.org /bugs/show_bug.cgi?id=549934
web, issue-tracking, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2019-11777
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary