# OpenSearch has ineffective TLS certificate hostname verification

Advisory record · `GHSA-x5hg-x4gv-j98m`

- **Identifiers:** `GHSA-x5hg-x4gv-j98m`
- **State:** Confirmed
- **Severity:** CVSS 2.2 Low
- **Critical:** No
- **Weakness (CWE):** [CWE-295](https://cwe.mitre.org/data/definitions/295.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md)
- **Published:** 7 May 2026
- **Updated:** 7 May 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 7 May 2026, 00:09 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `org.opensearch.plugin:opensearch-security` (Maven): affected `>=2.18.0, <2.19.4.0 || >=3.0.0, <3.3.0.0`; fixed in `2.19.4.0`, `3.3.0.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The opensearch-security plugin (Maven org.opensearch.plugin:opensearch-security) versions 2.18.0 up to 2.19.4.0 and 3.0.0 up to 3.3.0.0 has a regression that makes the plugins.security.ssl.transport.enforce_hostname_verification setting ineffective. A node holding a certificate signed by the cluster's trusted CA could join the cluster even if its hostname SAN does not match. Upgrade to 2.19.4.0 or 3.3.0.0; if you cannot upgrade, use more restrictive values for plugins.security.nodes_dn.

Written 3 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 2.2 Low, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** No score.

## Timeline

- 31 Oct 2026, 14:20 UTC: First seen by agentprime
- 31 Oct 2026, 14:20 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-x5hg-x4gv-j98m)

## Sources

- [GitHub Advisory Database: GHSA-x5hg-x4gv-j98m](https://github.com/advisories/GHSA-x5hg-x4gv-j98m)
- [OSV: GHSA-x5hg-x4gv-j98m](https://osv.dev/vulnerability/GHSA-x5hg-x4gv-j98m)
- <https://github.com/opensearch-project/security/security/advisories/GHSA-x5hg-x4gv-j98m>
- <https://github.com/opensearch-project/security>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-x5hg-x4gv-j98m>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-x5hg-x4gv-j98m/>. Everything for agents: <https://agentprime.io/llms.txt>.