# CVE-2025-37730: Logstash Improper Certificate Validation in TCP output

> CVE-2025-37730: Logstash Improper Certificate Validation in TCP output. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2025-37730
Last updated: 2026-06-17T09:15:19Z

- Published: 2025-05-06 17:29 UTC · Updated: 2026-06-17 09:15 UTC · Assigner: elastic
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- EPSS: 0.18%, 7th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-295

## Description

Improper certificate validation in Logstash's TCP output could lead to a man-in-the-middle (MitM) attack in “client” mode, as hostname verification in TCP output was not being performed when the ssl\_verification\_mode =\> full was set.

## Affected vendors and products

- Elastic: Logstash

## Tracked companies

- [Elastic Cloud](https://rewindex.com/company/elastic-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2025-37730)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2025-37730)
- [https://discuss.elastic.co/t/logstash-8-17-6-8-18-1-and-9-0-1-security-update-esa-2025-08/377869](https://discuss.elastic.co/t/logstash-8-17-6-8-18-1-and-9-0-1-security-update-esa-2025-08/377869)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2025-37730 · Markdown: https://rewindex.com/cve/CVE-2025-37730.md · JSON: https://rewindex.com/api/v1/cves/CVE-2025-37730 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:50:28.547Z