CVE-2026-91166 Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target
Attackers can intercept user traffic and hijack sessions by exploiting improper SSH host key validation in the web interface.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91166?
CVE-2026-91166 is a medium-severity vulnerability in warp-tech warpgate, published on 21 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.25.0 until 0.27.6, the browser SSH path in warpgate-web-ssh/src/manager.rs handles RCEvent::HostKeyUnknown without the presenting hop identity and instead passes ssh_options.host and ssh_options.port for the final target to KnownHosts::trust. In Prompt and AutoAccept modes, a jump host key can therefore be stored for the target address. A machine later presenting the jump host key at the target address can be accepted as the target, allowing interception of user traffic and a newly issued certificate when certificate authentication is used. The native SSH path is unaffected because it tracks each hop separately. This issue is fixed in version 0.27.6.
Which versions are affected by CVE-2026-91166?
How do I fix CVE-2026-91166?
No fix has been published for CVE-2026-91166 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-91166 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91166 exists.
Sources
Also known as GHSA-w9jj-vpw3-5r8f.