patrickhener goshs SSH host key verification bypass in tunnel

Quick answers

Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

High severity, with a CVSS score of 7.4, published 15 May 2026.

Which products and versions are affected?

goshs.de/goshs/v2 (Go) <= 2.0.6.

Is there a fix for This vulnerability?

A patch was published on 2026-05-15. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked over the network, in a software library.

Am I affected?

Check whether you run goshs.de/goshs/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The goshs '--tunnel' flag initiates an outbound SSH connection to 'localhost.run' using the 'ssh.InsecureIgnoreHostKey()' callback, which disables all host key verification. An attacker positioned on the network path (e.g., via ARP spoofing, DNS hijacking, or a compromised router) can intercept this connection and present a rogue SSH host key. Because the tunnel carries plaintext HTTP traffic, the attacker can read and modify all requests and responses, including headers, authentication tokens, and body content. This vulnerability was addressed in version 2.0.7 by implementing a Trust-On-First-Use (TOFU) mechanism.

Affected products

• patrickhener goshs <= 2.0.6

Timeline

• 2026-05-11: disclosed
• 2026-05-15: advisory
• 2026-05-15: patched

References

• https://api.github.com/users/offset
• https://github.com/offset
• https://api.github.com/users/offset/gists%7B/gist_id%7D
• https://api.github.com/users/offset/repos
• https://avatars.githubusercontent.com/u/114768995?v=4
• https://api.github.com/users/offset/events%7B/privacy%7D