CVE-2026-91166
Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.7
Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target
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.
- Record
CVE-2026-91166- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-297, CWE-923
- Updated
- 2026-11-02
EUVDEUVD-2026-84064
5.7
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.
- Record
EUVD-2026-84064- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
NVD
5.7
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.
- Record
CVE-2026-91166- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-297, CWE-923
- Updated
- 2026-11-02
OSV
5.7
Warpgate: Web SSH stores a jump host's key against the target's address, so it validates as the target
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.
- Record
CVE-2026-91166- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-297, CWE-923
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-91166 is a medium vulnerability (CVSS 5.7) in Warp-tech Warpgate, published September 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. No source names a fixed version.
References
github.com/warp-tech/warpgate/security/advisories/GHSA-w9jj-vpw3-5r8f
github.com/warp-tech/warpgate/commit/fb66ff74f979c22054f4d348cc0d9065cc67e5d3
github.com/warp-tech/warpgate/releases/tag/v0.27.6
github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91166.json
nvd.nist.gov/vuln/detail/CVE-2026-91166