{"id":"CVE-2026-85056","state":"PUBLISHED","title":"ZITADEL: MFA bypass via session reuse in Login V2","description":"ZITADEL is an open source identity management platform. From 4.0.0 until 4.16.1, ZITADEL Login V2 creates a browser session after password verification and can reuse that session for a later authentication request without verifying a user's enrolled TOTP, OTP, or U2F second factor. When the MFA step is abandoned and login starts again, session-validity checks require MFA only when the organization enables Force MFA or Force MFA for local users only, so a voluntarily enrolled factor can be skipped while completing an OIDC or SAML callback for a customer application. Login V1, the ZITADEL Console, Management and Admin APIs, and user self-management are not affected. This issue is fixed in version 4.16.1.","publishedAt":"2026-09-24T17:34:13.328Z","updatedAt":"2026-09-28T14:56:04.082Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["zitadel zitadel"],"affected":[{"vendor":"zitadel","product":"zitadel","versions":[{"version":">= 4.0.0, < 4.16.1","status":"affected"}]}],"references":["https://github.com/zitadel/zitadel/security/advisories/GHSA-9993-rfwp-rhwf","https://github.com/zitadel/zitadel/commit/049dbb25a56587fb3980c85c99819cad69f637db","https://github.com/zitadel/zitadel/commit/56f4798ed31fc1cfcd9a0e7f6f0152289d2fdc43","https://github.com/zitadel/zitadel/releases/tag/v4.16.1"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85056.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85056","state":"PUBLISHED","datePublished":"2026-09-24T17:34:13.328Z","dateUpdated":"2026-09-28T14:56:04.082Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-02T21:21:01.774Z"},"containers":{"cna":{"title":"ZITADEL: MFA bypass via session reuse in Login V2","descriptions":[{"lang":"en","value":"ZITADEL is an open source identity management platform. From 4.0.0 until 4.16.1, ZITADEL Login V2 creates a browser session after password verification and can reuse that session for a later authentication request without verifying a user's enrolled TOTP, OTP, or U2F second factor. When the MFA step is abandoned and login starts again, session-validity checks require MFA only when the organization enables Force MFA or Force MFA for local users only, so a voluntarily enrolled factor can be skipped while completing an OIDC or SAML callback for a customer application. Login V1, the ZITADEL Console, Management and Admin APIs, and user self-management are not affected. This issue is fixed in version 4.16.1."}],"affected":[{"vendor":"zitadel","product":"zitadel","versions":[{"version":">= 4.0.0, < 4.16.1","status":"affected"}]}],"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-9993-rfwp-rhwf","name":"https://github.com/zitadel/zitadel/security/advisories/GHSA-9993-rfwp-rhwf","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/zitadel/zitadel/commit/049dbb25a56587fb3980c85c99819cad69f637db","name":"https://github.com/zitadel/zitadel/commit/049dbb25a56587fb3980c85c99819cad69f637db","tags":["x_refsource_MISC"]},{"url":"https://github.com/zitadel/zitadel/commit/56f4798ed31fc1cfcd9a0e7f6f0152289d2fdc43","name":"https://github.com/zitadel/zitadel/commit/56f4798ed31fc1cfcd9a0e7f6f0152289d2fdc43","tags":["x_refsource_MISC"]},{"url":"https://github.com/zitadel/zitadel/releases/tag/v4.16.1","name":"https://github.com/zitadel/zitadel/releases/tag/v4.16.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-24T17:34:13.328Z"},"source":{"advisory":"GHSA-9993-rfwp-rhwf","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T14:55:51.988985Z","id":"CVE-2026-85056","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T14:56:04.082Z"}}]}}}