CVE-2019-11777
Improper Handling of Exceptional Conditions and Origin Validation Error in Eclipse Paho Java client library
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.
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
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2019-11777- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-346, CWE-755
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2019-11777- Weakness
- CWE-346
- Updated
- 2026-11-02
EUVDEUVD-2019-0656 No score
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.
- Record
EUVD-2019-0656- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-63qc-p2x4-9fgf
Improper Handling of Exceptional Conditions and Origin Validation Error in Eclipse Paho Java client library
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.
- Record
GHSA-63qc-p2x4-9fgf- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-346, CWE-755
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2019-11777- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-63qc-p2x4-9fgf
Improper Handling of Exceptional Conditions and Origin Validation Error in Eclipse Paho Java client library
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.
- Record
GHSA-63qc-p2x4-9fgf- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-346, CWE-755
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.eclipse.paho:org.eclipse.paho.client.mqttv3Maven |
before 1.2.1 | 1.2.1 |
org.eclipse.paho:org.eclipse.paho.client.mqttv3Maven |
before 1.2.1, plus listed versions 1.0.21.1.01.1.11.2.0 |
1.2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-11777 is a high vulnerability (CVSS 7.5) in Eclipse Paho Java Client, published September 11, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.83%, the 57th percentile. Fixed in org.eclipse.paho:org.eclipse.paho.client.mqttv3 1.2.1.