CVE-2025-37730
Logstash Improper Certificate Validation in TCP output
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Logstash Improper Certificate Validation in TCP output
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.
- Record
CVE-2025-37730- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2025-13629
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.
- Record
EUVD-2025-13629- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qrf7-ph5v-mj2v
Improper certificate validation in Logstash's TCP output could lead to a man-in-the-middle (MitM)...
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.
- Record
GHSA-qrf7-ph5v-mj2v- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-37730- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSV
Logstash Improper Certificate Validation in TCP output
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.
- Record
CVE-2025-37730- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSVBIT-logstash-2025-37730 No score
Logstash Improper Certificate Validation in TCP output
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.
- Record
BIT-logstash-2025-37730- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
logstashBitnami |
8.0.0 up to 8.18.1, 9.0.0 up to 9.0.1 | 8.18.19.0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-37730 is a medium vulnerability (CVSS 6.5) in Elastic Logstash, published May 6, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 7th percentile. Fixed in logstash 8.18.1.