{"id":"CVE-2026-105207","title":"ZITADEL 3.0.0 through 3.4.15 and 4.0.0 before 4.17.3 creates links between user accounts and external identity providers without verifying a primary factor or the caller's permission, including on identify-only Login V2 sessions and via …","summary":"ZITADEL 3.0.0 through 3.4.15 and 4.0.0 before 4.17.3 creates links between user accounts and external identity providers without verifying a primary factor or the caller's permission, including on identify-only Login V2 sessions and via …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-306"],"vendor":"zitadel","product":"zitadel","affected":["zitadel < 4.17.3","zitadel <= 4.19.4"],"published":"2026-10-04","updated":"2026-10-04","sourceUpdated":"2026-10-04T15:16:31.793","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-105207","references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-g8gj-gq47-xgf4","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zitadel-before-4.17.3-account-takeover-via-external-idp-linking","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-04T15:00:34.387Z","slug":"CVE-2026-105207","body":"## Overview\n\nZITADEL 3.0.0 through 3.4.15 and 4.0.0 before 4.17.3 creates links between user accounts and external identity providers without verifying a primary factor or the caller's permission, including on identify-only Login V2 sessions and via the User Service V2 AddIDPLink endpoint. An unauthenticated attacker knowing a victim's login name can bind their own external IdP identity to the victim's account and then sign in as the victim.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}