{"id":"CVE-2026-91165","state":"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.","publishedAt":"2026-09-21T18:53:03.854Z","updatedAt":"2026-09-21T19:26:22.695Z","severity":{"score":2.4,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["warp-tech warpgate"],"affected":[{"vendor":"warp-tech","product":"warpgate","versions":[{"version":"< 0.27.6","status":"affected"}]}],"references":["https://github.com/warp-tech/warpgate/security/advisories/GHSA-vvpj-p7j8-4rv4","https://github.com/warp-tech/warpgate/commit/e94425a08f501383a67316673749dcbd637c6ce3","https://github.com/warp-tech/warpgate/releases/tag/v0.27.6"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/91xxx/CVE-2026-91165.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-91165","state":"PUBLISHED","datePublished":"2026-09-21T18:53:03.854Z","dateUpdated":"2026-09-21T19:26:22.695Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-14T21:20:41.196Z"},"containers":{"cna":{"title":"Warpgate: Markup injection in SSO form_post return page via unencoded redirect/error values","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"warp-tech","product":"warpgate","versions":[{"version":"< 0.27.6","status":"affected"}]}],"references":[{"url":"https://github.com/warp-tech/warpgate/security/advisories/GHSA-vvpj-p7j8-4rv4","name":"https://github.com/warp-tech/warpgate/security/advisories/GHSA-vvpj-p7j8-4rv4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/warp-tech/warpgate/commit/e94425a08f501383a67316673749dcbd637c6ce3","name":"https://github.com/warp-tech/warpgate/commit/e94425a08f501383a67316673749dcbd637c6ce3","tags":["x_refsource_MISC"]},{"url":"https://github.com/warp-tech/warpgate/releases/tag/v0.27.6","name":"https://github.com/warp-tech/warpgate/releases/tag/v0.27.6","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":2.4,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-21T18:53:03.854Z"},"source":{"advisory":"GHSA-vvpj-p7j8-4rv4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-21T19:26:11.810922Z","id":"CVE-2026-91165","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-21T19:26:22.695Z"}}]}}}