---
id: CVE-2026-91165
title: 'Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux'
summary: >-
  Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. Prior
  to 0.27.6, the response_mode=form_post SSO return path in
  warpgate-protocol-http/src/api/sso_provider_list.rs uses serde_json::to_string
  inside ReturnToSsoPost…
severity: low
cvss: 2.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N'
cwe:
  - CWE-79
vendor: warp-tech
product: warpgate
affected:
  - warpgate < 0.27.6
published: '2026-09-21'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91165'
references:
  - url: >-
      https://github.com/warp-tech/warpgate/commit/e94425a08f501383a67316673749dcbd637c6ce3
    label: security-advisories@github.com
  - url: 'https://github.com/warp-tech/warpgate/releases/tag/v0.27.6'
    label: security-advisories@github.com
  - url: >-
      https://github.com/warp-tech/warpgate/security/advisories/GHSA-vvpj-p7j8-4rv4
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
epss: 0.00397
epssPercentile: 0.31106
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-21T19:26:11.810922Z'
ingestedAt: '2026-09-21T19:51:58.863Z'
---

## Overview

Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. Prior to 0.27.6, the response_mode=form_post SSO return path in warpgate-protocol-http/src/api/sso_provider_list.rs uses serde_json::to_string inside ReturnToSsoPostResponse without neutralizing a script-closing sequence. The vulnerable value can enter the script block through the attacker-controlled next redirect parameter stored by warpgate-protocol-http/src/api/sso_provider_detail.rs or through IdP-derived error messages that make_redirect_url concatenates without URL encoding. The IdP-derived path is reachable when the attacker controls a configured identity provider, or when the attacker controls the email or username claim on an attacker-controlled account and the configured identity provider permits the required unvalidated claim format. A victim must complete the form_post SSO flow for the injected markup to be rendered. The Warpgate Content-Security-Policy blocks injected JavaScript and event handlers, so the demonstrated impact is content spoofing, a false login form, or a meta refresh rather than script execution. This issue is fixed in version 0.27.6.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.