{"id":"CVE-2026-91165","aliases":["EUVD-2026-84063","GHSA-vvpj-p7j8-4rv4"],"status":"published","title":"Warpgate: Markup injection in SSO form_post return page via unencoded redirect/error values","description":"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.","severity":{"version":"3.1","score":2.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00397,"percentile":0.34402,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-09-21T18:53:03Z","modified":"2026-10-28T02:30:42Z","products":[{"vendor":"warp-tech","product":"warpgate"}],"references":[{"url":"https://github.com/warp-tech/warpgate/security/advisories/GHSA-vvpj-p7j8-4rv4","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/warp-tech/warpgate/commit/e94425a08f501383a67316673749dcbd637c6ce3","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/warp-tech/warpgate/releases/tag/v0.27.6","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/91xxx/CVE-2026-91165.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91165","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-91165","title":"Warpgate: Markup injection in SSO form_post return page via unencoded redirect/error values","description":"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.","status":"published","published":"2026-09-21T18:53:03.854Z","modified":"2026-09-21T19:26:22.695Z","cvss":[{"version":"3.1","score":2.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","level":"low","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:19:52.773089Z"}],"euvd":[{"id":"EUVD-2026-84063","description":"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.","status":"published","published":"2026-09-21T18:53:03Z","modified":"2026-09-21T19:26:22Z","cvss":[{"version":"3.1","score":2.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","level":"low"}],"updated_at":"2026-11-02T17:28:04.588371Z"}],"nvd":[{"id":"CVE-2026-91165","description":"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.","status":"published","published":"2026-09-21T19:17:15.19Z","modified":"2026-09-24T21:25:27.05Z","cvss":[{"version":"3.1","score":2.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","level":"low","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:50.368368Z"}],"osv":[{"id":"CVE-2026-91165","title":"Warpgate: Markup injection in SSO form_post return page via unencoded redirect/error values","description":"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.","status":"published","published":"2026-09-21T18:53:03.854Z","modified":"2026-10-28T02:30:42.644176355Z","cvss":[{"version":"3.1","score":2.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","level":"low"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:45:20.269367Z"}]}}