CVE-2025-23390 Fleet doesn’t validate a server’s certificate when connecting through SSH
Fleet fails to validate SSH server certificates by default, allowing man-in-the-middle attacks against connections.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-23390?
CVE-2025-23390 is a medium-severity vulnerability in SUSE fleet, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-295
Which versions are affected by CVE-2025-23390?
7 open source packages ship an affected version, including github.com/rancher/fleet.
| Package | Affected | Fixed in |
|---|---|---|
github.com/rancher/fleet Go | From 0.11.0 | 0.11.7 |
github.com/rancher/fleet Go | From 0.11.0 | 0.11.7 |
github.com/rancher/fleet Go | From 0.12.0 | 0.12.2 |
github.com/rancher/fleet Go | From 0.12.0 | 0.12.2 |
github.com/rancher/fleet Go | From 0.9.0-rc.1 | 0.10.12, 0.11.7, 0.12.2 |
github.com/rancher/fleet Go | From 0.9.0-rc.1 | 0.10.12 |
1 more packages
github.com/rancher/fleet Go | From 0.9.0-rc.1 | 0.10.12 |
How do I fix CVE-2025-23390?
Upgrade github.com/rancher/fleet to a fixed version for your release line: 0.11.7, 0.12.2 or 0.10.12.
Is CVE-2025-23390 being exploited?
There is no known exploitation of CVE-2025-23390 in the wild and no public exploit code.
Sources
Also known as GHSA-xgpc-q899-67p8, GO-2025-3649.