CVE-2026-90623 andreashappe cochise SSH Host Key ssh_connection.py asyncssh.connect certificate validation
An attacker can bypass SSH host key validation in the cochise library, enabling man-in-the-middle attacks against remote connections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90623?
CVE-2026-90623 is a medium-severity vulnerability in andreashappe cochise, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A weakness has been identified in andreashappe cochise up to 0.4.1. Affected is the function asyncssh.connect of the file src/cochise/ssh_connection.py of the component SSH Host Key Handler. Executing a manipulation can lead to improper certificate validation. The attack may be launched remotely. The attack requires a high level of complexity. The exploitability is told to be difficult. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
Which versions are affected by CVE-2026-90623?
How do I fix CVE-2026-90623?
No fix has been published for CVE-2026-90623 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-90623 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90623 exists.
Sources
Also known as GHSA-2w8j-c6w5-f5gp.