What’s Vulnerable › Vulnerabilities

CVE-2025-23390: Fleet doesn’t validate a server’s certificate when connecting through SSH

• Severity: medium (CVSS 6.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-19
• Weakness: CWE-295

Description

A vulnerability has been identified within Fleet where, by default, Fleet will automatically trust a remote server’s certificate when connecting through SSH if the certificate isn’t set in the `known_hosts` file. This could allow the execution of a man-in-the-middle (MitM) attack against Fleet. In case the server that is being connected to has a trusted entry in the known_hosts file, then Fleet will correctly check the authenticity of the presented certificate.

Affected products

• SUSE Fleet: from 0.9.0-rc.1 before 0.10.12; from 0.11.0 before 0.11.7; from 0.12.0 before 0.12.2 — fixed in 0.10.12, 0.11.7, 0.12.2

How to fix

Upgrade to a fixed version: SUSE Fleet 0.10.12, 0.11.7, 0.12.2. Check the vendor advisory for mitigations.

References

• https://bugzilla.suse.com/show_bug.cgi?id=CVE-2025-23390
• https://github.com/rancher/fleet/security/advisories/GHSA-xgpc-q899-67p8

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