GHSA-x5hg-x4gv-j98m
OpenSearch has ineffective TLS certificate hostname verification
GHSA-x5hg-x4gv-j98m is a low vulnerability (CVSS 2.2) in org.opensearch.plugin:opensearch-security, published May 7, 2026. No source lists public exploit code. Fixed in org.opensearch.plugin:opensearch-security 2.19.4.0.
- Severity
- 2.2 LowCVSS 3.1, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
2.19.4.0org.opensearch.plugin:opensearch-security +3 more
Description
Description
A regression was introduced in OpenSearch 2.18.0 that caused the plugins.security.ssl.transport.enforce_hostname_verification setting to be ineffective. When this setting was enabled, OpenSearch did not verify that the hostname in a connecting node's TLS certificate matched the hostname of the connection. This could allow a node with a valid certificate (signed by the cluster's trusted CA) but an incorrect hostname SAN to join the cluster.
Impact
Clusters running affected versions with hostname verification enabled did not receive the expected protection from this setting. A node presenting a certificate signed by the cluster's trusted CA could join the cluster regardless of whether its hostname SAN matched. This regression does not affect certificate validation itself — only the additional hostname verification check.
Patches
This issue is fixed in OpenSearch 2.19.4 and 3.3.0.
Workarounds
Use more restrictive values for plugins.security.nodes_dn to limit which certificates are accepted for node-to-node communication.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.opensearch.plugin:opensearch-securityMaven | 2.18.0 up to 2.19.4.0 | 2.19.4.0 |
org.opensearch.plugin:opensearch-securityMaven | 3.0.0 up to 3.3.0.0 | 3.3.0.0 |
org.opensearch.plugin:opensearch-securityMaven | 2.18.0 up to 2.19.4.0, plus listed versions 2.18.0.02.19.0.02.19.1.02.19.2.02.19.3.0 | 2.19.4.0 |
org.opensearch.plugin:opensearch-securityMaven | 3.0.0 up to 3.3.0.0, plus listed versions 3.0.0.03.1.0.03.2.0.0 | 3.3.0.0 |
What each source reports
GitHub Advisories Score used
OpenSearch has ineffective TLS certificate hostname verification
Description
A regression was introduced in OpenSearch 2.18.0 that caused the plugins.security.ssl.transport.enforce_hostname_verification setting to be ineffective. When this setting was enabled, OpenSearch did not verify that the hostname in a connecting node's TLS certificate matched the hostname of the connection. This could allow a node with a valid certificate (signed by the cluster's trusted CA) but an incorrect hostname SAN to join the cluster.
Impact
Clusters running affected versions with hostname verification enabled did not receive the expected protection from this setting. A node presenting a certificate signed by the cluster's trusted CA could join the cluster regardless of whether its hostname SAN matched. This regression does not affect certificate validation itself — only the additional hostname verification check.
Patches
This issue is fixed in OpenSearch 2.19.4 and 3.3.0.
Workarounds
Use more restrictive values for plugins.security.nodes_dn to limit which certificates are accepted for node-to-node communication.
- Record
GHSA-x5hg-x4gv-j98m- CVSS 3.1
- 2.2 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSV
OpenSearch has ineffective TLS certificate hostname verification
Description
A regression was introduced in OpenSearch 2.18.0 that caused the plugins.security.ssl.transport.enforce_hostname_verification setting to be ineffective. When this setting was enabled, OpenSearch did not verify that the hostname in a connecting node's TLS certificate matched the hostname of the connection. This could allow a node with a valid certificate (signed by the cluster's trusted CA) but an incorrect hostname SAN to join the cluster.
Impact
Clusters running affected versions with hostname verification enabled did not receive the expected protection from this setting. A node presenting a certificate signed by the cluster's trusted CA could join the cluster regardless of whether its hostname SAN matched. This regression does not affect certificate validation itself — only the additional hostname verification check.
Patches
This issue is fixed in OpenSearch 2.19.4 and 3.3.0.
Workarounds
Use more restrictive values for plugins.security.nodes_dn to limit which certificates are accepted for node-to-node communication.
- Record
GHSA-x5hg-x4gv-j98m- CVSS 3.1
- 2.2 Low
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.